@gg
Completing a novel AND actually submitting it is a great achievement that requires celebration! Too many people never get to that stage. You can call yourself an author, even a novelist, now.
That said, if becoming an author as a career is you goal, I suggest the following:
/Write the next story!/
Being an author is almost always about the next story. I HIGHLY suggest short pieces. I'd probably take one of my existing main or secondary characters and write about the next events in their lives, or backstory. Keep it short, aiming for the low side of 1000-5000 words. When you finish one...
...Write the next.
Practice is essential, and your writing will get better!
Think about the sequel to this novel, or come up with an idea for the next big book, too. Set a goal of writing it in less than six months (every 5 years is not going to make you a living), and it doesn't have to be perfect. That's why there are editors, beta readers, and proofreaders. It needs to be complete, however. Your shiny new publisher or agent is going to say, "That's nice. Tell me about your next story."
You CANNOT rely on your publisher to promote your work. Promotion may end up being partially or solely your job. Your publication month may feature a best selling author, and that author will get all the advertising. That happened to me...
You're on Mastodon. That's a good start, but USE HASHTAGS (see below) Begin a blog, for example on Wordpress, in the fediverse, or elsewhere. Create a simple web site. Post interesting things you found in your research, articles found on the Internet, your thoughts about writing, your journey to becoming published. Daily if you can; keep it going. You want people to come back, to know your name and associate it with interesting things. Make it exciting, if you can come up with those ideas. Be sure to use the name you are going to publish under; make it into a brand name.
Oh, and those little short stories you wrote? You can publish those on your website or to your blog so people can get a taste of your work. Consider writing serial fiction.
So. Is that enough to do while you wait? What are you waiting for?
The world isn't going to discover how wonderful you are without you making sure they know.