If you have a few short stories you’ve already written, you could start posting those to get a feel for uploading and scheduling as you write a longer story
I agree with everyone else saying to make sure you have a buffer. My main story was mostly finished before I started uploading (so I was doing last minute edits as I uploaded instead of trying to write an episode)
If you’re someone who enjoys writing last minute, then go for it, but if you struggle with ending stories, it’ll hurt your rep to drop a story if you lose interest part way through.
Whenever you decide to upload, definitely utilize the author’s note section! It doesn’t have to be long or overly personal! But a tiny little note to your readers can go a long way!
Make sure your thumbnail has your title and that you can read it when it’s super small (like on the phones app). You can make covers in Canva (that seems to be the popular option) if you’re not an artist. 
Work on your summary! Having a good hook for your story is absolutely vital! 
And try to interact with people! Replying to comments on your story, interacting here on the forums, maybe making an IG or twitter account! 
Lastly, make sure to have fun. This is supposed to be enjoyable. Unless you end up making a ton of money from this and quitting your day job, this is just a hobby and it’s supposed to be fun. It’s always good to push ourselves to get better at something we enjoy (and not every stage of that is 100% fun), but this should be a good thing for you overall 