Summarize:

You don't need to rush in the morning just because you spent half an hour picking out your outfit! Go for something between casual and original. But remember you are making first impressions so what you wear kind of dictates a part of your personality, so don't go far outside your comfort zone. Expectations are overrated. You just got out of elementary school, no need to wear makeup or do anything fancy with your hair. If you're not comfortable with it, don't do it! All these middle school girls you see in magazines have makeup on solely for the advertisements. Going your first day with no makeup is quite the bold move itself, as it shows you have confidence in yourself and that you don't need makeup to attract attention! This will wake you up and make you smell fresh and feel great. (Remember some nice deodorant to top it off.) You do not need to haul your whole home with you. All you really need for your first day really is a few snacks, a pencil or two and the basic supplies. Bringing extra pencils and snacks may be helpful, but not necessary. The higher grades don't bite! If you're feeling daring enough, go and try to make some friends who are older than you, as they have gone through your grade and may be able to give you some pointers. Mingle with some other stranger that may be hanging around too. If you can't find a loner to make friends with, go take a look at a map of the school and try to get the know the place, after all, you're going to be spending a few years here.
Pick out your outfit the night before. Avoid feeling that you have to wear makeup. Take a shower in the morning. Take only what you need. Seek help from people already in middle school. Make some friends while you're waiting for school to open.