Write Lots of Drafts, Make Lots of Edits
Nothing Worth Reading Was Written in a Single Draft
Writing is not a one-and-done kind of thing. You might be able to write something interesting and fun in a single draft, but every first draft can be improved by writing a second draft. And every second draft can be improved by doing at least one editing pass. And so on.
There will come a point where further rewriting and editing is barely helping your story improve, and when you reach that point you can stop, publish what you have, and start again on a new story.
But you can do a lot of work on a story until you get it to the point where it is as good as you can get it.
Having ideas and writing them down is an important part of the writing process, but it's definitely not the only step.
Also, once you are starting to get your story to the point where it is as good as you can make it, that's a good time to show it to someone else. A fresh set of eyes will see your story in a new and different way, and the feedback they give you can really help you (as long as they make sure they are giving you constructive feedback!).