It's sort of like that here, but not quite in that way. All stories occur at once (or however you see fit to conduct your character's timeline, which is liquid here depending on your play style. You may have your character in multiple threads if say for instance one event precedes another.)
Here, the entire forum is comprised of separate locations, with varying geography, cultures etc (see:
The World if you haven't already) and players create stories together in threads. Each thread tells the story of SotE, in a manner of speaking, as I think Rhi (grand Admin) has said at one time or another.
The best place to get started would be the
Plotting Center and you can browse what others have posted in terms of desired threads, available characters,
open threads, etc. Or you may also post one yourself, inviting people to take part in the story - or stories - you've made for your character. Plot style (pre-plotted or going with the flow) is all up between you and your partner, there's no set way you have to do things. You may also make an open thread in a specific location yourself and invite people to join in. Or you may peruse another player's characters and message them about a certain character your interested in writing with. Those are just some ways you could get started.
I hope that helps!