Answer 1

Go through these and learn all you can:
https://docs.godotengine.org/en/3.1/
https://www.sololearn.com/Course/CPlusPlus/
https://www.sololearn.com/Course/CSharp/

If you're getting into the gaming industry, I'd also advise learning your way around Unreal Engine and Unity 3D as well since many companies use them and they're the two mainstream engines at the moment.

https://www.UnrealEngine.com
https://www.Unity3D.com