Welcome!
Nothing wrong with just being here to read, we've got some great stories here, and writers are all big attention whores so new people to check them out are always welcome. Be sure to leave a rating and if you can, at least a short comment on any story you finish. Constructive criticism is encouraged here as well so don't ever worry about being too blunt or anything like that.
In fact the quickest way to rack up some points and commendations and become respected in the community is actually in reading storygames and leaving detailed reviews.
If you have any particular genre or kind of story you're looking for, let us know and I'm sure somebody can give recommendations.