What you'il realize is that it is not just about the language but more about the basic principles, that often repeat across different languages.

Especially if you know one Object oriented programming language most other will start making sense to you.

I've always liked javascript. You can use it for all kinds of Software and there are a lot of resources around to teach you. A lot of the modern web is written in javascript Frameworks.

I believe Python is also good to learn the principles.