I just built my first two AR-15 pistols and had them at the range to test their reliability and function.  I didn't have as much time available as I'd wish (the local club focuses on trap and skeet; rifle and pistol time is very short) but I'm at least comfortable enough with them to put them into my home defense plan - even as a club they're better than empty hands but, so far, they've fired flawlessly.

The problem is, the guns are firing flawlessly but my shooting sucks.  Today was just basic functional testing from a single shot to a couple in the mag to a couple of full mags.  The shots were all over the target at 25 yards - basically 90% within a 12-inch circle and a couple outside of even that.  I wasn't focused on exactly the best shooting and I was not using any kind of a rest but, even so, I know I need to have much tighter groups.  I didn't site in the red-dot or the back-up sights so I wouldn't expect to have the groups on the X but I do need to learn how to shoot the pistol more accurately.

Can you recommend a youtube channel or other good tutorials to get me started?  The United States Shooting Academy is a pretty famous range in Tulsa and they have tactical rifle classes but not tactical AR-15 classes.  Any other training suggestions?  I'd say I don't have the money for a trip to some of the other famous training places in Nevada or Arizona.  I guess I could if I wanted it badly enough; I just hope to not have to travel that far for training.

Zero your rifle first, buy 500 rounds, and practice. Then go from there.

My couple experiences with tactical classes have been that they basically start with the assumption that you have the basics down. We've started with a quick drill or two so the instructor gets a baseline then we've worked into shooting drills, mag changes, transitioning to pistol, malfunction drills, etc. Plus room entry, shooting through small openings, crazy position shooting, etc etc.

My point is that from what I've seen a tactical class may not be your best bet for getting instruction on shooting fundamentals like sight alignment, trigger squeeze, how to hold the rifle, and so on.

I always like Jerry Miculek videos, he keeps it simple and you know the man can shoot. Biggest thing is practice - dry fire to get your trigger smooth and make sure your dot stays on target when you pull, get your grips comfortable, and shoot a lot. I'm sure you can find a class that hits those basics too if you need.

And this isn't to discourage you from a tactical class when you're ready - it's one of the coolest things I've done lately and I'm lined up for a 2-day class here in a couple weeks.

Start slow and focus more on your body positioning, stance and basic marksmanship. Do not worry about the groups or shooting fast until you have developed the muscle memory. You can do a lot of this by dry firing or using a training rifle. A good airsoft rifle is worth the investment. I have had people laugh when I told them I train with an airsoft rifle or when I tell my son to treat it as a real rifle, but the Army had us train a lot using paintball and airsoft and they are great assets since they are cheap and you can just about shoot them anywhere. Work on getting on target, reloads and changing positions before dumping a bunch of ammo on the range. There are some great videos on youtube, but please use common sense because there are just as much bad info as there is good and keep in mind that there is always more than one way and the "best" way is the what you are most comfortable and proficient with.

All very good suggestions and I will pretty much follow them all.

One problem I am trying to solve is the basics that might be preparation for a tactical class.  Many of the rifle skills don't apply to a pistol - and many do.  How to grip a pistol, for instance, is different.  No shoulder stock to press tightly against the shoulder.  To keep from getting a tube in the face, I have to actually push the gun away with my weak hand while triggering with my strong hand... or at least that's what it seems like to me.

To improve my pistol shooting, I've been studying and practicing the skills taught by Chris Sajnog (free stuff only so far).  I looked for anything similar for AR pistols and didn't find anything even close.  No drills, no practice tips, no grip tips, etc.  Breathing is breathing; what I learned in the service applies for all guns, but it seems that's almost the commonality between shooting an AR rifle and an AR pistol or even my 1911 EDC.  Oh, another Sajnog tip that will, no doubt, help on the AR  pistol is focus on the front site (I assume that translates to "on the dot" for red dots).

But I can't find any tactical drills videos or other practice tips specifically aimed at the AR pistol.

Just so I understand correctly, you do not have a brace on your pistol? If you don't, you're correct; you won't find very much on them. The reason for that is because shouldering provides a lot more stability with that platform. Remember, it is legal to shoulder an AR pistol equipped with a brace--NOT A STOCK--so long as that brace is unmodified. If you have a brace, and are using it, the mechanics are the exact same as with a carbine.

Regarding the other stuff, there are actually a lot of similarities between pistol and rifle shooting. Hand placement on the weapon is the major difference.