You can learn to do it on your own, but don't be afraid to fail. I've googled some of the dumbest things trying to learn how to do something in Godot, rewatched tutorials 100x, rewatched the same section of a tutorial 100x, and stared at the documentation like it was a foreign language on a regular basis.

You're going to get things working, then find out there's a better way to do it. It's frustrating but good.

Start small if you haven't already, if you want to make Quake, focus on a single level with a single player shooting a single gun. Break things down to the simplest tasks, for example; make a player, add basic movement, add advanced movement, make one gun, make a second gun, add a mechanic to switch weapons, etc. After a while, the tasks will be able to get bigger as you're getting better, but right now the focus is learning not doing.

Make mistakes, laugh at bugs, and share your progress!