Hi, games are pretty easy to get started on. It's mainly just a matter of controlling how big a game you try to do. If you've not written any game yet, then it's good to start simple, by making your own version of things like Tetris, break out, pong, that of thing, just to learnt he basic of moving objects on the screen, handling collision detection, keeping score, menus, etc... Then you can move on to multiplayer (either turn based or realtime).
From the games you've mentioned, you want smooth motion, so something like XUI2D or the LibGDX library would work well for some 2D game to get started. It is possible to write 3D games with B4X tools, but you may find using an engine like Godot might be better. There's plenty of tutorials (including my own on using LibGDX with B4A) on youtube covering all this.
One mistake I see a lot of new game coders doing, is trying to learn Unity or Unreal, both are huge engines that have way more features than you'd need for small game projects (and end up with big install sizes on mobile devices too, which puts off players with basic phones).