After working a desk job and being lazy for a few years I have been getting out and walking/jogging at a trail. I would like to try to increase the difficulty so I was looking at ruck packs that can utilize the ruck weight plates from go ruck, Rouge, titan....

I need to be able to carry probably a 20lb weight plate and a hydration carrier.

Any recommendations on a beginner pack?

Also, what shoes are you guys using? Trail isn't paved or that even so I was considering a short hiking boot

Let me know what you guys are using and if you have any recommendations. I dont need to carry anything, this isn't for a bug out or anything. Just looking to make my miles a bit harder

This might be more general than you want, but ...

Make sure your pack fits you correctly.  Stores that will fit the pack to you are best, as they generally have good equipment and staff with a clue.  Get one that includes a hip belt, or your shoulders will hate you.  I have an Osprey and an old Arcteryx.  But for humping loads around for fitness, you don't need Tier 1.

Hiking boots are nice on uneven terrain.  (I really dislike rolling my ankles.)  Try on a bunch of brands, because they'll all fit your foot differently.

I always just stuffed climbing ropes and gallon jugs of water into the pack.  I'd hike up the mountain with the water in the jugs, then dump the water out at the top to save my knees on the way down.

Get a sandbag can wrapit in duct tape.

if you have to ditch it is cheaper and softer

I haven't rucked in a bit, but I generally like to use sacks of rice for weight. I try to aim for a single sack, if possible. Rice is economical and feels better on the back than plates do. Depending on how it is packaged, it can also have a bulk to it that a plate doesn't have which also helps facilitate using the cinches on the pack to make the weight less awkward. In the pre-COVID world, I enjoyed doing certain charitable ruck-race events, which usually included a food donation element. By using rice, I could train with the same weight that I was going to carry on race day.

Footwear has a heavy personal preference element to it. I wore the same footwear that I trail run in  (La Sportiva Bushidos) and do fine on (hard packed) dirt trails, doing about a minute per mile slower than my standard trail running pace. If I was concerned about terrain, or was planning a walk instead of pushing it, I would wear a pair of decent hiking boots (my current pair are some Italian made Karrimors). While I will hike in military type boots at times (and own a couple of different types), commercial hiking boot offer a lot of advantages.

I was too cheap to spring for a ruck plate, so I made one out of a stiff plastic cutting board with 10# barbell plates zip tied to it. You can add or subtract plates as you wish. I trimmed the board to fit in my pack. It's lasted many miles with no problems.

Goruck Rucker is a great pack for carrying a weight plate and water. Also good for carrying stuff to work, but not really that big of a pack to use for more than that.

I wear merrell moabs as my every day shoe and use them to tuck in.

I started with a 5.11 Rush24 and some steel targets. I have since then moved up to a GORUCK 26L GR1 and some various ruck plates.

Have you considered a weight vest? Or plate carrier if you have one? If you aren’t using s pack for anything else, this might be a better route.

Not quiet in line with what you're looking for, but you could get started tomorrow on this.  I don't have a real use for a bunch of ruck gear outside of the exercise, and I don't need to spend the money on it right now.

I just use a 5.11 pack, 3L bladder, and some loaded Pmags, because no one had weights early last year when I started.  You could throw in water bottles, 2 liters filled with water, whatever.  That ends up with just shy of a 20 pound pack, which was plenty to get you started.  Then I added a kid on my shoulders, so any where from 50 to 65 pounds.

I just started wearing my plate carrier though, which is a little over thirty pounds.  So now I push anywhere from 60 to 75 pounds, at least four nights a week for at least three miles.

All that office chair dull back pain and neck stiffness, totally gone after starting that routine.  Its been pretty good.