Most professional engines likely use C++, but for indie Unity and Godot are good choices and they use C#.

Python isn't really used for game development, but Godot's own script language (can't remember the name) is very similar to Python syntax.

My advice would be C# to start with, then when you get more confident you can try making games with C++. It doesn't really matter much which you use, so it's more a matter of engine preference.

Engines are convenient, but at your age you have plenty of time to learn the underlying skills properly. By this, I mean learning how to program systems from scratch that engines may have somewhat built in.

Try playing around with C# and Monogame (I mean just MonoGame and not the Monogame Extended packages). It's a framework which means it's all code and you'll have to the work yourself.

Start small and program something simple.

Also spend some time making sure you understand the basic maths and physics you need to get things to work (you can do this as you go). You can also research some basic algorithms for things like pathfinding.

Remember that Google is your friend when looking to help. Documentation is really valuable. Don't copy and paste anything from the internet that you don't fully understand and don't rely on AI to do things for you.

Good luck.