I like to keep things as simple as possible.
Honestly the easier we keep the "should do's" when it comes to fat loss, the sooner you'll see results, and the happier both of us will be.
So, two fast tips for you.
1. Get enough sleep tonight. Lay out your gear for tomorrow and have everything ready to go. If you are going to have a little coffee or tea before the class, get your supplies ready.
2. Plan your eating for tomorrow. Protein and vegetables should be your choice if you are really working for fast fat loss and changes in your body. Plan on having a quick protein drink right after your workout, or plan on eating a few eggs and some vegetables for breakfast.
That's it. Just do those 2 things and you'll be on the right path.