When learning new skills, frustration can kick in. That’s counterproductive and doesn’t help achieve the goal. The good news is you’ve quite a few skills to master, all need lots of practice.
The hard skills are buoyancy and backfinning. Buoyancy is hard as you need to learn how it feels and predict when to dump or when to exhale. Add to that a drysuit (if applicable) and you’ve double trouble as it were. The frustration is learning the subtle cues and learning how much to dump or inflate.
Learning to be relatively stable in the water needs time with some form of datum, a wall or platform edge is good. Face that marker and try to be still without holding on. 10 minutes is about it before frustration sets in. Then swim off and practice something else — or maybe just dive for a bit.
The toughest buoyancy issue is changing depth. You’re going from stable, descending/ascending then back to stable. If you’re shallow, then move up/down 3 feet and hold that stable position for 1min, then ascend/descend 3ft and repeat.
At some point you’ll be doing a full ascent from the bottom which needs to be under control. That’s a more difficult skill as you need time to learn but you can only do a limited number of ascents before your ears start to block. Deeper ascents should be limited to a very few a day.
Everyone struggles to master backfinning. It’s just time and patience.
Frog kick, flutter kick (from the bent knees) and helicopter turns as all relatively straightforward. Just practice these on every dive.
Some places have a buoyancy assault course — hoops, bars, hurdles, turns, etc. they’re great fun to play on.
Have fun and don’t get upset when it doesn’t work. You’ll find it’ll be easier when you’ve slept on it.