I was once a fool like you :)

Mike McShaffry’s book “Game Coding Complete” is a good guide to the practical side of using a game engine IRL to get things done.

It’ll give you a good idea of how things should be shaped in order to be useful, and some things you can “skip ahead” to. Off-the-shelf engines have to be extremely general in order to be flexible enough to be useful to many customers, so game devs have to put in the effort to make them more specific. You’ll have to start off by being specific, if you have any chance of actually finishing something.

Eberly’s book “3D Game Engine Architecture” deals with the nuts and bolts, the rigorous academic engineering stuff. It’s pretty solid, but it’s aimed at making a general-purpose engine, which is beyond the scope of a one-person project.

Backing up though… You don’t have any language or library opinions? You might need 5-10 years of experience doing general programming (or game dev) before you can sustainably tackle this, or else you’re likely to paint yourself into a corner.

Edit: Probably the biggest PITA with game engine dev is testing. If you’re not already an expert in setting up test harnesses at multiple levels of detail, you’re gonna find it impossible to keep moving after a few months.

Good luck!