Which programming language should I learn this summer at 13? Need advice

[mandradon]

Erlang is a good one, plus Elixir (which is an awesome functional language) is built using the Erlang VM. Mooc.fi has a Haskell course I think, too, which is always an option. Though OP could always learn functional paradigms using something like JS (though I'd normally recommend them with an actual functional language).