Good job, I took a beginners class a couple months ago and it was awesome.
As has been pointed out get out and practice your skating as much as you can. During the classes push yourself as far as you can when it comes to doing the drills. Don't be concerned with falling, if you're not falling at this point you're not pushing yourself to your limits. Don't be worried about falling, your gear WILL protect you.
Outside the ice, work on your legs, back, and core. These are the primary areas you'll be using while skating. No matter how much you work out in the gym before hand you're going to be sore after your first session, skating and holding yourself up on the ice takes muscles you didn't even know existed
Most of all just have fun. Don't worry about if you're not good enough, or if others are better just work on yourself. Take your time doing the drills and get them right. If you have an opportunity to scrimmage at the end of class take it! Actually playing the game will help you advance so much. Organize some shinny with your fellow classmates as well if you can!
Good luck, it's super fun!