learn both until you know which one is your favorite.
There is a hoard of professional Java or C# developers that invalidate the idea that you need to know more then one language to program professionally.
While this might seem odd to a hn reader, where there is weekly blog posts of comparing languages or trying out the new shiny thing at a startup.
One need to remember the audience is single digit percentile of the computer industry. The rest of the industry actually use jdk or .net in the enterprise.
They used Java. The rest of my programming jobs, -large and small, has been either Java, PHP, .Net and once a bit of Delphi. Lately there's also been a lot of TypeScript.
There's been a few jobs I wanted to apply for but couldn't because I'm not good enough with C/C++ and Qt.
Maybe things are different in Silicon Valley but around here the most exotic language I see is Python.