You can sell as a private seller on chrono. Many factors will go into how long it will take to sell such as price, condition, desirability of the watch. I believe papers refer to all documentation you got when you bought the watch. Things like warranty cards, manuals, receipts.
Honestly the whole process is pretty simple and easy. I have gotten plenty of tire kickers and low ball offers on my listings there. You’ve just got to be patient for the right buyer. Best of luck!
Also, r/watchexchange is a great place. Consider listing there as well!
Looks like it’s 38mm according to their website. Sizing largely comes down to personal preference. That being said if it were me, I would stay in the 36-38mm area. I think it would be right in the sweet spot for you!