Hey, welcome to the site!
You could read the articles in the "Help & Info" section first just to get some questions answered, and then you can start reading and rating some storygames. I suggest starting with the featured ones (the ones that show in the box for each category), so that you can read some quality content and see where the top bar's set. Oh and don't forget to review if you can, it's always well appreciated by the authors.
If you then plan to write something, the advice is always to take your time and to start with a medium-small project, not something that's too long or complicated. There are also good tips on Mizal's profile, and Wibn just posted a useful motivational thing for newbs.
Feel free to ask for advice here on the forums.
