I would suggest sitting down with your teacher and having him really go over the sheets with you. That way you know where you need extra practice to improve your scores.
Typically, you are given a "1", "2", "3", etc based on how many people danced in your category. A single heat can have several levels (newcomer, bronze I, bronze II, etc) and several age groups (ladies A, B, etc) dancing at the same time. The different levels are usually separated by a space. You are judged against the others in your age and level category. If you danced Bronze I, you will not be judged against those dancing Silver II, etc.
I looked up score sheets for the comp you're talking about. These score sheets show the heat number. Find your heat number(s) and your partner's number (on his back while you danced). The letters listed to the right of the "No." are the letters assigned to the judges judging that particular heat. The numbers to the right of your partner's number are what each judge scored your dance in that heat. To the far right is your placement in that heat.
Hope that helps. It's a little difficult to explain without using visuals...