That's why they call it practice. TT is a sport with a high learning curve, and without a trainer helping you it's simply really hard to get a good basic technique down.
I'd focus on point 3) and get your FH and BH to the point where it feels like you don't have to think through the entire stroke.
FH and BH drive
FH and BH push
FH and BH topspin drive
Exercise these things with placement, not speed. You want to be able to hit 5 consecutive balls into the right place, then 10, then 20, and work your way up as far as possible.
This builds automation, feeling, confidence.
Now, I understand that doing only this week in week out can get boring. And I also hear you want to learn about serve and receive.
If you can hit a stroke into the right place reliable, you can start learning to serve it. So for example, when you are OK with your FH drive going where you want it to go, start learning a FH drive (no spin) service.
Learn to toss the ball up and hit it.
(some like to learn by letting the ball drop on the table and then hitting it, that may be a good intermediate exercise but I think learning to toss is very important)
Do it slow first, take a step back from the table if you feel like that works, and then just take a bucket of balls and serve serve serve.
If you don't have a bucket of balls (get one) and want to do it with a training partner, just serve to each other.
If your training partner is more advanced, you will simply not be able to return most serves until you have more basic skills. You can ask them to tone down the service, but that means they get less out of the exercise.
Or play a game where you are the only one serving. If they can finish the ball too easily, make a rule where the first ball can't be a point.. Get creative!
First set, all FH service
Second set, all BH service..
I deliberately left out most of the service receive stuff. 80% of that will fix itself by doing these basics and doing them thoroughly.
If you want to learn more about what spin does on your bat, bounce a ball on it. Make a small swipe, then catch the ball with the bat again and see how it changes.
Then try to adjust the angle of the bat to see if you can get that sidespin ball under control.
If you have a spare ball, draw a line on it with a waterproof marker and use it for this. You can see the spin that way.
Also, bounce against a wall, and figure out what changes when you make a push stroke vs a drive stroke.
All of this might sound trivial but it really helps to build great basics.
