The only place allowed to post a query for critique is in the Query Hell section of Share Your Work, which is AW's password-protected workshop area.
But to post anything for critique, you need to have made 50 posts first. This ensures that you spend a bit of time here and get to know folks, and learn your way around the forum. And, of course, you're welcome to critique other people's queries and stories in Share Your Work. That's the fastest way to get 50 posts under your belt, and has the bonus of demonstrating that you intend to be a contributing member of the forum!