Python, JavaScript, or (if you have a Mac) maybe Swift.
(Probably not Java or C++. They're too big.)
But really it doesn't matter much. CS snobs used to say that "BASIC causes brain damage" but a whole generation of programmers proved that to be wrong. The important part is to keep going and not stop. After you learn one language, learn another. There's no such thing as a good programmer who only knows one language.