Long story short, I am having two issues.

I bought my first baitcaster rod/reel combo at Bass Pro (7ft Med, Fast action) because it was $120 and seemed like a fair deal (normally $150 for the combo and $199 if you bought them separate).  There are cheaper combos that have good reviews but I like left handed reels so that limits combo options.  Anyway, they spooled it with 12 lb mono for me for free.  I haven't ever fished mono and I have had a horrible time with it so far.  These are issues that I haven't ever had before.  I've lost a handful of lures so far.  The line snapped off during the cast twice!  One was a weightless Senko and the other was a strike king KVD 1.0 crankbait.  Neither has any significant weight so I don't understand how my lure is snapping the line and flying through the air and giving me a gnarly backlash.  I also had a small mouth...a small one...pull my lure off last night.  I had it to the bank and watched it swim away with another crankbait in its mouth.  My son caught the same size smalley with his mickey pole and the strike king minnow crank bait two nights ago.  The night before he reeled in a small cat fish and he catches a handfull of bluegill ever time we go out....the lake doesn't have monsters in it and I would expect my line not to snap off when I get a hook.  So, is the line totally shit or is this somehow user error?  I have the break turned up since I'm a newb to baitcasters, but I adjust the spool tension every time I put a new lure on...which has been frequent since I have lost so many lures.

The second issue is getting snagged.  I decided to try out the old Ned Rig and got weedless jigs.  I've never used this setup before but the lake we fish has smaller fish so why not.  I know it has a lot of trees and rocks in the bottom so I thought weedless rigs would help.  I lost 3 LAST NIGHT because they are getting hung up.  Am I screwing this up or is this pretty common even with a weedless jig?

In case you are counting...that is 3 Ned Rigs, 2 crankbaits and a Senko all gone...since Saturday.  I would really like to get this figured out so my son and I can spend more time fishing and less time tying lures and fixing backlash

Simple answer is to change the line to what you are used to.

Where the mono is concerned, the type of knot you use is critical to it's strength. I use Palomar knots for 95% of the knots in monofilament; the remainder are haywire twist knots and have never had one break off while casting.

The other thing is you might have the spool tension set way too tight or are unintentionally thumbing the reel too tight, which will cause a whiplash at the end of the line and usually break it. Set your spool tension for the average weight of your lures and only change it if you go to a lighter weight one. I have bait casters set for 1/4 - 3/8 oz. lures and 1/16 to 1/8 oz.; that way, all I do is switch rods when I want a different weight lure.

As far as "weedless" rigs go, the only ones I've found to be weedless are Texas or Carolina-rigged worms; the rest all suck.

I typically use a clinch knot, but I can try the palomar and see how it goes.  I use Segaur Invizx Floro on my spinning rods.  I can give that a try I guess.  They told me they don't recommend Floro on baitcasters for beginners because it is more expensive and it's easier to damage when you get  a backlash.  It won't be any more expensive than losing gobs of lures I guess.  Plus, I have yet to have a backlash that I couldn't fix.

For the spool tension and thumbing issue, I check it with each lure.  I just set it so that it gives me a steady drop.  I don't think it is too tight, but I can get it a little looser and see how it goes.  I will make sure to mind my thumb.  What I have been trying to do is keep my thumb clear on the initial cast and then feather it about mid cast so that I can get it stopped before it hits the water.  I can get a solid 30 yard cast even with the small/light lures I use in this little lake.  I will see if the palomar and less tension will help with the breaking.

Prior to trying the Ned Rig, my go to was a Texas Rigged worm.  I agree with you that it's about the best option.  I was just trying something different to see if I could grab some smaller fish since this lake is full of them.

I usually use braided line on my bait casters; never had good luck with floro line on them.

The few times that I have used monofilament line, I used the "limp" line as it seemed to cast better.

All I had to was read that it’s your first bait-caster. Sure, the line may have something to do with it but it’s really the learning curve.

I went through probabl a mile of line and $200 worth of lures with my first, lot these many decades ago.

Using the clinch knot? Make sure the line is wet when you knot it, don’t pull hard on the tag end, it may burn the mono and make it weak.

How are you casting? Are you casting like you’re throwing the Senko a mile like on a spinning rig? Don’t need to do it that hard.

This video is pretty good for a baitcasting rookie.

Do you use a leader of any kind or straight braid?

Did you go through line and lures because of backlash or what was the issue?

Thanks for the video.  How he describes setting the brake is how I've been doing it.  That being said, i will go a little more free spinning just in case.  I haven't been casting overhand at all.  I was practicing in my yard and realized that I could cast more accurately with a simple just a flip from about the 3 o'clock position.

I will try the palomar tonight.  I keep the knot wet when I tie it but I could be burning it I guess.  Since I have no experience with mono (on my reels...I'm assuming my sons reel has mono on it) I'm flying blind to some degree.

Try the trilene knot. Basically an improved clinch knot that Berkley came up with.

Straight braid in freshwater; monofilament leader in salt water.

Braid for baitcasters with flouro leader if fishing clear water.

Backlash. Lots of backlash. Then adjusting the mags and friction.

Then it got to adjusting my casting technique. As in not pretending I’m casting into the surf with a spinning rod.

You’ll get the hang of it and wonder why you ever used anything else.

I’m at the point where I can almost baitcast empty line; I don’t need much weight to get it to carry.

I’ll add I don’t like braided line. Kinks, and when you do get the lash it’s a lot harder to untangle.

I don't fill the spool completely with braid- 3/4 full at most. Makes clearing a backlash easier.

I almost always use berkley mono because it's cheap, try a different knot. Mono will carry memory after 4-5 fishing trips, but cheap enough to strip some out and tie more back inline. Check your rod guides to insure they are smooth.
What type of technique are you using to fish the jigs, what size are you using, and what type of jig head? Your rod might not be heavy enough to bump those jigs over structure. I normally use a heavy action 7'4" or a 7'11" flipping rod to fish jigs in a lot of cover, it helps.

I've lost a lot of line....but its because jigs get stuck or the line broke.  I haven't lost any from backlash yet.  I have been able to fix all of my backlash with a little patience.

What kind of line do you use if you don't like braid?

What is your go to Braid?  I haven't ever used it.  I don't know quality from trash or what size braid to use.

I used the Palomar last night and used a heavy Jig....no issues with breaking.  I will stick with it for a while and see how it goes.  Thanks

I bought the zman weedless finesse shroomz to try with the ned rig.  I think they are 1/5 oz.  I don't have technique name, but I am casting it out in front of cover, letting it drop, popping it off of the bottom and reeling little by little back to the bank.

The rod is a 7 ft medium power fast action tip...It is essentially THIS combo but Medium and not medium heavy...my exact rod isn't shown online

I’d also check the little eyelet that the line goes through to make sure there isn’t a burr or sharp edge that could be cutting your line.

When you lost lures, was it at the knot or back at the baircaster?  If at the lure it’s your knot, if at the bait caster it could be a number of things

I also put just enough line in my baitcaster to be a little longer than I can cast. I’d rather change it out regularly with smaller amounts of line than spool it on thick and get a backlash and lose it all.

Switch back to braid and run a 5-6 foot floro leader. Knot choice is very critical. The uni knot is great for you leader and the clinch not is ok if that is what you are used to. I stepped away from mono 15 years ago, and I am not going back.

To help, make a cast and then pull out 4 or 5 arm lengths of line from the spool. Add a piece of electrical tape to the spool so that it is a “stop” for the line when you get backlashes.

You don't want your spool too loose.
Adjust the spool tension so that the lure will slowly pull out and drop (not free fall) if you click the freespool button with the rod held horizontal. As you get better, you will get a better feel for this but even for experienced users, this setting does not change much at all.

If you have magnetic spool breaking, set it to about the 50% mark. Depending on how aerodynamic the lure I am throwing is, I will adjust it up or down between 25% and 75% (more aerodynamic = less dynamic braking).

One thing that can really screw you up, especially if you are transitioning from a spinning reel ,is that a baitcaster is more sensitive to whipping the rod when you cast. Your cast stroke needs to be smooth so that as the rod unloads (flexes back to straight) it does so at about the same time you lift your thumb off the spool.
Ideally, when you lift your thumb, the rod has just unloaded, the line is taught, and the lure is headed toward the target. This keeps the everything moving at the same speed. If you really whip the rod, often times when you release your thumb, the rod is not yet unloaded and the lure whips past the end of the rod, causing a temporary slack in the line. When the lure travels far enough to take up that slack, the spool has already been spinning and the backlash is already starting. When the lure gets 15 or 20 feet out, the backlash occurs, the spool stops suddenly, and will reverse direction and wind the line up backwads.

I find that braid is much more forgiving in getting out backlash than mono. You also should be able to pick out the backlash with a little practice (you will get plenty as you learn). I get one every now and then (especially if trying to cast into a gusting wind) and I can't remember the last time I had to cut the line as opposed to getting it unwound.

From a success standpoint I find that a 5ft flouro leader helps tremendously in the number of strikes I get. If you get a line shy fish like a walleye braid right up to the lure = less strikes. Also, if I am not fishing for something that requires a metal leader (i.e. Northern Pike) I forego the snap swivel and tie directly on to the lure. Once again this helps with line shy fish. Use an Albright knot for tying braid to flouro. Simple to tie and doesn't weaken the flouro like some other knots do.

I could explain it but old Fluke does it better Start here.

Thanks for all of the replies fellas.  I yanked the bass pro mono off last night.  I am going to probably switch over to a co-poly or braid and give it a go.  I will keep you posted on how it goes.

I ended up buying some copolymer line.  It seems to be mono with a floro outer layer.  I have had zero issues with it breaking, backlashing, coming untied etc.  We will see how that goes over the next few weeks, but so far so good.

Still getting hang ups on the jigs? What are the shapes of your jig heads and what is the bottom/structure of the bottom of the lake?

I figured out how to set up the weedless ned rigs so that I am not having as many issues.  I've snagged a couple small mouth with it since I made that change as well.  It's maybe a 5 acre lake and no boats/kayaks etc are allowed so I can only speak to what is on the edge.  It is mostly rock along the bank.  There are grass bedding areas along the bank.  Probably a 1/4 of it is essentially off limits because of the tree cover.  You could certainly fish back there, but I have been seeing a lot of snakes so I am keeping my son in the more "groomed" areas where they are easier to spot.  There are also a decent amount of small logs in there.  Generally when we get a serious hang up it is a big piece of wood.  One section has some moss cover, but since it is a small community lake they have the bubblers that sort of push it to one corner.

I don't really know if that answers your question at all, but that is generally what it is like.  There are other places that are better to fish, but we can walk to this lake so we fish it probably 5 times a week now.  Since the fish are small it is a good place for my little guy to learn.  He did two years with safety bobbers and hot dogs as bait.  This year I have let him fish with a crank bait (kvd minnow) and he has caught a ton with that.  I have also let him use my spinner bait and he has a couple on it as well.  He is starting to ask questions about the weight of the lure and how he should reel it in etc.  I think I have him hooked.  Going to bass pro today because we lost his favorite lure over the weekend with a nasty snag in his favorite spot....next to a tree....it's still in the tree lol