Before diving into your own projects, I always recommend browsing a few of the top rated (and not so top rated) stories just to get an idea of what community expectations are, a sense for the different branching structures, and what the editor is capable of, etc.
Since I see you're writing fanfiction, be aware that they may massively cut down the audience here unless it's written (like any other story) with a mind to introduce unfamiliar concepts as you go to people who will likely have never encountered the setting or characters before.