Stawr_Gurl:
I commenting start with simple things because for some things around the own "code" (source code) in a program, you have learn some things usually shared with all programming languajes...... for example, imagine you have in a game 4 kind of options for anything (a menu, a "conversation-answers" replies etc.... the simple way of manage it could be 2 forms .... with If-Else statements or with a Switch-Case function in the code..... and things like that are someother ones in a program ....then if you started with a simple game, the experience you get around how structure the code etc is exactly that im reffering..... (also of course know things like different kinds of variables you can create/handle and more things cos i viewed people doing games in Unity/Unreal and they neither know what is a FLOAT variable ......yes....is for that i said you DOCUMENTATION, BOOKS etc for you learn all around you going to front
Once playing with simple games, give jump to some graphic 2D Games with sprites, dealing with transparencies, frame to frame animations for the sprites, timers, backgrounds etc etc and make for example a 2D RPG, or a Space Invaders game kind... (here the most complex is make a good scrolling screen system and the collisions) or a 2D or 2.5D Graphic Adventure and reinforce your coding knowdledge with other things like deal with multiple objects in inventory...... conversations between player and characters in the Graphic Adventure, puzzle's creation (combining the use of a item in inventory with another item or something in the own screen scenario, creating a system smart for handle all the screens in a cartesian X Y estructure (with a array of structures for example)) and much other things that not impossible to deal with them but yes will require a bit of you think how make it in good way in the program code
And Finally when you expert with 2D games etc, try jump to Unity / Unreal / Godot and start with 3D stuff
a last advice remember the RAM is finite, a good managing of what and when you load/unload things in memory is the KEY for a good game flow (i see lot of people loads all in memory in Unity etc.....and soon or later they always come with same question ....."im out of RAM.....i have too much things in my 1st level of the game and what i can do??"
ah yes, and of course any of that books related to Videogames programming also good buy.
I say you books cos in a good book you can find much more examples, information etc than in a video-tutorial (people thinks all ressolved with a video youtube tutorial but they are wrong..... a book is always better)
but overall take it with calm and go learning at your own rythm you can handle..... in general all that of programming and videogames is so BIG and cover so many things that is normal it "overload" your own mind-capacity at some point so go with care.