You could probably find tutorials online that relate to these things. For games, you want to use C++. It’s faster than C# by far, however it’s one of the lowest level programming languages and as such it does not really help you. If you get an error it generally tells you that there’s been a mistake, but C++ doesn’t really tell you how to fix it. For starters, you probably want to focus on basic things like unpacking the code in the C++ template. It contains code that tells you how the character is able to move, but it won’t make much sense to you unless you have a fairly decent grasp on C++.
I’m currently watching this channel - the guy knows a lot about programming and takes you through all of the main stuff. He has stuff like C++, Java, Python and other languages. https://www.youtube.com/channel/UCnAdXkr17iQS8YcYl0LhPdw
As for creating materials and textures, there are probably tutorials relating to that on youtube that relate to 3ds max. You’ll just need to look them up.