One of the first things I read about sailboat racing back in the early 80's was "Your finishing position will be the same as your starting position, give or take 10 percent."

To move from B Fleet to A Fleet, work on your starts. The best reference on how to get good starts comes from Rick White's book/video. The best way to learn how to get good starts is to go to one of Rick White's Sailing Seminars. I have been to two, and they are worth every penny (including driving my motorhome from Michigan to Key Largo pulling my boat)!