Very much an aside and downvote if too much of a tangent - if I wanted to create a command and conquer like game (ideally like generals where it is 3d) - how would I go about doing that? Is Godot an appropriate engine for that?
Unity has a much larger community and will have much more in the way of intro tutorials, so I started there.
But regardless of the engine you choose, you'll probably spend the better part of a year building tiny games (like tic-tac-toe -> pong -> breakout -> Tetris -> etc) before you can execute on anything more complicated (like a 3d RTS).
That said I agree 100% with building tiny games in an iterative fashion to understand the engine you're using, or taking a very narrow "vertical slice" to help flush out where the technical or game mechanic issues will be.
There's a wealth of good engines out there today where you're building on in some cases literally decades worth of development that can accelerate a lot of the work involved in building a game(and there is a lot of work there).
If you are looking for a 3D tutorial, this one seems pretty good: https://www.godotrts.com/courses/rts-game-development-course... (but I haven't used it myself).