There are many versions of "Now What?"
But first, if I may suggest-- I want you to take a well deserved break and step outside to smell the roses! Breathe in that fresh air you've been missing while hunched over your keyboard and muttering character dialogue to yourself.
Here's a few of my ideas on what you can do with that completed manuscript.
1. Write the sequel
Yep. While the characters are fresh in your mind and you're on a writing high, jump right in and start working on book number two. That is, if your story warrants a sequel. If you aren't ready to write an entire sequel, at least jot down an outline of your characters. Like, where did they leave off? What did you plan on having them do next if your first book kept going.
But first, put it away for a selected period of time. Two, Four, Six weeks. Whatever the time, mark you calendar. The point of editing is to see the things in your writing that you couldn't when you were knee deep in the plot. Editing is about refining the story, adjusting awkward scenes, fixing messy dialogue, you get the point.
Using the "Find" feature will be your best friend.
Example: After reading your book, you realize your favorite word was "Original" and you used it over and over and over. Don't stress! Come up with some other ways to say original. Then use the find feature to skip throughout your book and replace those pesky words.
3. Send your book to Beta Readers
This is a critical step in the writing process. Having real people read the book! Since they are who you wrote it for in the first place. If you wrote a YA Historical Fiction book, then find a young adult to read it. You can ask family and friends to read it (they will love it-- because they love you). And if you still can't find anyone willing to read your book and give their feedback, join a writing circle. There are multiple websites and chapters of writing organizations with plenty of folks just like you, who are all willing to be a Beta Reader. Plus, you might make a new friend in the process!
4. Submit finished manuscript to an open publisher
There are publishing houses out there who accept completed un-agented manuscripts. If the thought of finding a Literary Agent is scary and overwhelming, you can always submit directly to one of the publishers who have open submissions.
Make sure you vet them, do some web searches, make sure they are legit and not a vanity press. Vanity Presses will try and coerce you to putting up your own money to publish your novel. You should never have to pay a legitimate publisher to publish your book.
Check out DAW Books, Inc. if you have a Fantasy or Science Fiction manuscript ready for submission! They have over 50 years of experience publishing debut and established authors. Their submission process is super easy and you hear back from them in 3-4 months if they want to publish your work.
Self-publishing can be an excellent way to publish your first book and start earning revenue every time someone downloads your e-book or orders a print-on-demand copy. Royalties can be much higher with self-published books. Meaning, you can sell fewer copies and earn more money. This allows you to build up a fan base as you work on that sophomore novel.
6. Query and find a Literary Agent
My last suggestion is to use the query process to find a Literary Agent. Querying is the "art" of writing letters to pitch your book and yourself to a Literary Agent. This can be a very harrowing process for a first time author. However, if you want your book to be published by a traditional publisher who (hopefully) pays a royalty for your book and puts their marketing dollars behind the launch, then this is the route for you. Traditional
Publishers will ONLY accept your novel through a Literary Agent. Your Agent is going to use his/her/their contacts in the literary world to find the right publisher for your book. They will also help you navigate your contracts and secure additional revenue streams for your book like International Rights and possible TV/Movie rights.
Warning! Traditional publishing can be a very long process. There is a lot of waiting involved. So, if you are not willing to spend the next one or two years immersed in your novel's debut-- Self-Publishing might be the avenue for you. Immediate gratification.