"So, I have one story idea down, but most people on this site have several stories going on at once, so I wanted to start another one."
Doing that is not a good idea. Having several stories at once when can severely slow down your progress, and is a mistake I've done in the past. Two stories is fine, but three and more might potentially slow progress down. Stick to your first story idea about some sort of kingdom, or whatever.
Oh, regarding to your request onto co-authors, I am willing to help out in one of your storygames. Just keep in mind that I am not on this site 24/7.