It's great that you want to show your love for Stardew Valley by creating your own fan art. If you feel ready to share your creations with the world, there are several ways you can do this. Firstly, if you're an artist who creates new work regularly, you could set up a dedicated Instagram account to show your work. If you're a bit shy, and only want to share in a safe environment, you could join a private Stardew Valley group on Facebook, and share your art in there where it will only be seen by other fans. If you're happy for anyone to see your art, then you can put it on an art website such as Art Station or Deviant Art. You could even share it to the Stardew Valley subreddit.