Again, I'd urge you to start small. For the contest entry I'd planned a four character multi-POV story extraordinaire. When there were two days left on the clock (after working for 10, I wasn't slacking), I put that behemoth off and made a work that would have been for all purposes a side story to a side story in the original work.
It was my best decision this year so far, I was able to get a story up and running for the contest, and learnt a ton of things on the way. For this story (The Devourer), I'd targeted 54 pages on Day 1, ended with 18 done by 2 AM. Woke up and realized that within another 24 hours I'm not going to be able to crunch out the remaining 36, so cut off a bunch of second half content, and scaled down to 40. Realized the circumstances would cause more endings than I'd planned, so went back up to 44. Did the work suffer a bit from the revisions? Frankly, yes. But did I complete a work I was able to share and get feedback from? Absolutely, and that's all that matters, not writing a 200 page novel. You will learn things you didn't know you didn't know when you make your first work, so keep it small.
Let me offer another angle, starting small helps readers figure out whether or not they like your style of writing, and whether they want to read more. Accordingly, that lets you find people who will be interested in and supportive of your later (better) works, and believe me they'll be more motivation than a thread can ever be. Offering a 200 page story to a first time reader is like offering a window shopper a five layered wedding cake with fireworks and dancers instead of a cupcake (and expecting them to sit in front of you and eat that massive cake because you spent so much time on it). It's overkill, and not in a useful way.
I wrote an article on how to start your first game, from my own experience, you could read that in case you'd like a structured approach. A primer on writing your first Storygame