I just completed my first quarter of Drexel's ACE program and the best advice I can give you is to relax during the remaining time before you start. There's really no way for you to get a head start on this program. Just make sure you have solid knowledge of basic A&P, and you'll be fine. It's easier to learn new information quickly for principles or health assessment class if you don't have to refer back to your A&P book constantly.
I desperately wanted to get a head start over the summer before I started ACE in the fall, but quickly realized that there wasn't much I could have done ahead of time.
Seriously, just take this time to get money together, spend time with family and friends, and just relax. The time between now and March will fly by, so enjoy it. Drexel will give you enough tasks that need to be completed before your start date to keep you busy. For example, you will get a letter in the coming months providing you with the name of a drug calculations book that you will need to buy and study. You will be tested on this material (completely self-taught) during the first month of school.
If I think of anything else, I'll be sure to let you know.
Take care & good luck!