If you're not already following it, check out Handmade Hero (https://handmadehero.org/). Great, free video series from Casey Muratori that guides you through building a game from scratch.
I am following it, slowly but surely.
Unfortunately, he's up to day 75 and i'm still on day 11.
This is actually one of my goals too. If I can recommend, the godot engine[https://github.com/okamstudio/godot] is my main source of inspiration and learning.