I have a bit of a different experience from others because I actually originally drafted my novel for traditional publication. I had all of book 1 written and spent a lot of time editing it before I eventually made the decision to post it as a webnovel.
I made that decision for one major reason: in preparing the novel for traditional publication, I got a little obsessive over my editing. I got so obsessive, writing and rewriting things constantly to make it "better," that I ended up sucking all the fun out of the story. So I decided to forget traditional publishing and post the story for free online instead - it started as a project that was supposed to bring me joy, and somewhere along the way, I lost sight of that.
That's the one thing I'd do differently - from the start, I'd try to remember why I was writing. I'd try not to get so lost in what I thought "made a good book" that I ended up turning my project into one that was just miserable for me. Especially with fantasy, it's easy to get caught up in consistency, worldbuilding, tying plot threads together, etc. I fell into that trap, so it's one I'd warn you away from!
Now, I've fixed the story to bring back that original spark. It doesn't have a huge following yet, but at least I'm having fun with it again! (Here's the link, if anyone's curious: https://tapas.io/series/Fractured-Magic/info)