Do small simple projects at first and try to complete each one. Watch tutorials, learn the workflow of making games. Focus on understanding why something works and why another doesn't. Don't worry if things look too complicated, it's normal and it has happened to every great game developer. Nobody wakes up knowing how to make good games, that all comes from a lot of practice and dedication.
You will need a way to keep yourself motivated because trust me, sometimes you will feel like quitting all together, like you know nothing and it's not worth it . There are far more easier things to do. Whenever you feel like this, it means you need to take a break, not to quit. Take some time doing something else totally unrelated and when you come back you will be feeling much better. Sometimes I solve my problems by just leaving them alone and coming back to them later. Somehow the solution pops in when am not even thinking about it.
Watch devlogs too. Its a good source of motivation, seeing other people work their games and overcome their challenges is very satisfying.
Anyways YouTube is your best friend, to keep things short.