It’s not so much a specific programming language, but the actual skill of conceiving and making something that’s gonna put you ahead.
Pick one of the more common languages like Python, Ruby or Elixir (or on the Microsoft Windows site - I’d say Visual C).
Then make something good with it. A small but real project that solves one of your own pain points. This way you will actually give a damn about enough to continue for the long haul.
What you want to do is learn the skill of making something from scratch until its ready to be used by an audience.