You did it! You wrote a freaking book! No matter how long or short- you wrote a book! Congratulate yourself, that is a big ass achievement right there!
You can do whatever you want with your book, you can send it off to publishers and see if its good enough to be made into a real, physical book. Or you could post it onto sites like Wattpad, and see who would read your book. Do whatever you want with it because its yours at the end of the day.
YOU JUST WROTE A BOOK.