I'd recommend two things. The first is what you and the others have already mentioned: check out the articles in the Help & Info section, link on the left.
The second thing is, while you still have nothing to lose in your storygame, to just hover over and click all of the controls in the interface. You will learn a lot of things that might not be covered elsewhere just by stumbling across them. Play around with the different settings and see what fits you best. You might like the controls offered by the advanced editor or you might like to keep things simple and focus on the writing aspect. Now is the best time to do this, because you'll expose yourself early to things that may make your work much easier down the road.
Bonus tip: start with a short storygame, pour your heart and soul into it, put it out there, and see how it goes. You'll come out better equipped for more serious projects that way.