I'd try some of the Multimedia / Audio Linux distributions. I believe there are some which have everything set up for you and you can just try and explore. Notably Ubuntu Studio, AV Linux
Other than that, LMMS and Ardour, Qtractor, ZRhythm, Rosegarden, MuSE, or Mixxx for DJing... There's generally a lot. DAWs, trackers, sequencers, synthesizers... you can do professional multitrack recording or just mess with your guitar or sample some electronic music...
It's a bit difficult as a beginner, since there are a lot of options and they all have different user interfaces and you might need to learn a few concepts first. And /or read the documentation or watch some Youtube tutorials.