Write things. Write badly. Write in as many different genres as you can think of. Finish things. You’ll learn more about yourself as a person and a writer if you finish what you start. You’ll learn where you’re strengths are, what your weaknesses are. You’ll see weird themes pop up in your writing. Don’t worry about writing well just yet, just worry about writing. Writing well comes with practice and you’ll never improve if you never let yourself write badly. Not everything you write is going to be published, so don’t worry if your story isn’t quite what you thought it would be. That’s what the rewrite is for.