Lawnmower won't start?

We have a Briggs & Stratton Brute 625 push lawnmower... bought it new last month and have only used it once so far. It sounds like it wants to start, but it can't quite get there. It has fresh gas and oil and everything is hooked up right. It has a primer on but no choke or anything else. I tried the B&S website, but it wasn't any help. What could we do to get it running?