Welcome to you, rontdtarchala. (We gotta get you a shorter nickname!)
To start a new thread, you go to the board where you want to post it. This board,
Office Party, is for silliness, and there are boards for all sorts of serious writing boards (and different non-writing boards)
here. Notice there's a board for Newbies and a handy-dandy FAQ board, too.
Anyway, once you're at the board you want, you'll see a "New Thread" icon at the top left. Click on it and you get the blank slate for your new thread. Warning: Although it's easy to edit the text of your post if you see a typo, subject lines are not fixable, so type carefully!
Maryn, glad to meet you, and returning us to our intentions thread