What programming language to start with?

Depends on what you want to do with your knowledge of programming. I got into programming when I was a teenager with Python, but I quickly moved onto C++ because my ultimate goal was game development. If your goal is web dev, learn Javascript, HTML/CSS and maybe dabble in PHP (not really required, but would be good to have under your belt).

C# and C++ are both really popular languages for game development, although I say C++ is superior. (I'm extremely biased :ultralul