Beginner general help for execution

Hello to everyone.
Apologies for the naivety of my question but i really arrived to a point i am thinking if is worth going on with this beautiful game or not.

At the very beginning i had read is normal to sistematically lose in casual online playing, so i thought i simply needed to progress from a disordered throw of basic moves to a more structured way of fighting with combos, special moves etc.
I started to play in training mode. The point is that i can’t understand really why the special moves happen 1/10 and often actually the result is different from what indicated in the character official guide.

I just make an example, Bison hells warp. I was expecting that pressing medium punch and medium kick (easy right?) i could easily get the movement where he disappears and appears behind the opponent. Instead…nothing, he simply makes a move with his hads saying: meaningless! Thats it. Why?
There are at least thre moves i never never got it, psycho blast, psycho inferno, psycho charge, psycho judgement. Never, not once. To me it seems simply impossible

Chun li: spinning birt kick, 1/20 attempts. Kikoken: 1/50 attempts…

I wonder if i miss some basic info of the game, like for example certain moves can be done only in certain states, or gauge numbers…to be honest i ignored that part, i simply try to execute the moves as indicated in the guide.

thank you very much