One of the best feelings a writer experiences, is that moment when they can write the words The End on their manuscript. A warm, fuzzy feeling takes hold and it spreads to every part of our body. It's a feeling of accomplishment. After all, writing fifty-thousand words in thirty days is a tremendous feat, and you should cherish every bit of your accomplishment. Congratulations, you have the start of something beautiful, and that's a lot more than many writers can say.
So now what? Once that giddy feelings subsides, that dream of becoming a published author is one step closer to reality, but don't jump the gun. Resist temptation and put that manuscript away. Let your brain rest for the month of December. Enjoy the holidays but don't touch your novel. Write something else if you have the urge, AND under no circumstances should you even think about submitting your novel to an agent or uploading it to Amazon and Smashwords.
Why? Because it's not a novel. Not even close. Not yet.
Right now, what you have is fifty thousand words (or more) of a potential story. There are grammar mistakes and spelling mistakes. The plot probably wanders off a few times, and you characters are two-dimensional with dialogue that is weak and flat. Is that what you want people to read? Your novel needs revisions, edits, and more revisions. It needs the plot holes filled and all plot bunnies put to rest. In other words, it needs to be the best it can be. Yes, there are some writers who can send out their first draft, but you're not one of them. Besides, those writers have honed their skill for years, maybe decades. They know how to craft a story, but even then, they'll hold back and do revisions and edits as well.
You want to be one of those writers. The ones who take the time to learn how to write, to create stories that keep readers coming back for more. That is how you become successful. That is how you become a true author.