Don't be intimidated-- we're all people. Well, most of us anyway...
I like new RPers. They usually have the best ideas... if not the potential to write great stories and great characters.
I tend to be one of the more long-winded RPers. I like to write out details... what's my character thinking? Does she have any nervous habits? How does she talk? What does she see? ... and then I totally go over board with details. My character does maybe... one or two specific things, but I have quite a bit of prose to carry it along... and how I write is dictated by what I've recently read too. Ugh.
Don't worry about your writing. We're just glad to have you 'ere! =)