I was recently asked what my best advice is for young writers. Beyond read (a lot) and write (a lot), my main advice is to live life.
Travel (even if it’s just to the next town over), meet new people (even if it’s only Starbucks employees), run (even if you can only do it for a hundred yards), fall in love (even if the other person doesn’t love you back), knit a sweater (even if it turns out hideous), do stuff that scares you (even if it’s only doing any of the things on this list so far).
The point is, by expanding our life experiences, we can make our stories and character interactions richer and more authentic. And even if you never finish your novel (or find an agent or a publisher), at least you lived life to the fullest you could.