If your goal is to make a game, these are exactly the things you should be learning, not reinventing your own architecture. If you just want to learn about engine internals, then sure go for it. But games (even very simple ones) are an incredible amount of effort that has nothing to do with programming. If you actually want to make one you should be working at the absolute highest level of abstraction possible so that you can start doing the real work; building the mechanics, creating the art, designing levels, writing the story, music, sound effects, etc. etc. Many of the succesful indie games these days are made almost completely via "no-code" visual tooling. It's basically a meme at this point for programmers to want to make a game and just end up wasting their time writing a naive engine.