As another already said, start with something simple.
There are lots of game engines out there that don't even require programming skills at all. If you're more of a visual learner that might be the way to go. A game engine like Crey might be a good starting place.
But if you're like me and want to know what happens "Behind the scenes" in a video game, I would check out QB64 for the Qbasic programming language. Some people might not remember, but back in the 80s and 90s there were tons of books and tutorials on how to make very simple Qbasic games. Heck, in just the first week of High School Qbasic class I had already figured out how to make a decent text adventure and from there I played around with graphics and other features.
One way to gauge how "easy" or "simple" a programming language is: Research how many lines of code it takes to do something simple, a prime example being the famous "Hello World" project. Some programming languages can accomplish this in 2 lines of code and others require 5 or more.
I hope this helped and welcome to game development -- it's fun!
EDIT: Just saw that you said you know C# already so in that case I'd skip QB64 and stick with that. I'm planning on learning C# myself.