C is probably the best choice if you're the kind of person that wants to learn fundamentals-first - perhaps start with Learn C The Hard Way. That's cool, but that doesn't personally work for me. I'm primarily motivated by creating, not learning, so I prefer to learn how to do things first and then learn the intricacies of it later. If you are that kind of person too, I think JavaScript is a decent choice:
Very well documented and covered by tutorials.
Runs in web browsers, game engines, servers and hardware.
Few language constructs to learn.
No tooling needed to get started.
Great package manager with lots of pre-built components, allowing you to build lots with little code.
ClapCreative.com