The first day of middle school can be totally intimidating, but try not to freak out. You're in a new building, you have new classes, new people, and on top of that, you're faced with new responsibilities and you're expected to be more mature; but you will get through it. Here's how to ace your first day.
Start by knowing where your classes are going to be. You don't want to be running around lost, not knowing where to go. So, see if you have an older friend or maybe you can even get your hands on a map of the building. That way, you know where you're headed.
Pick out what you're gonna wear the night before. That way, you're not wasting time in the morning, but also you're able to visualize your first day. Think positively. Think about how awesome it's gonna be, and all the fun you're going to have meeting new people.
If things don't go perfectly, don't worry. Your reputation is not sealed for life. My first day of 7th grade, the plastic bag that all my new books were in, completely ripped in the middle of a hallway and my books went everywhere. But I'm pretty sure that, after a little while, no one even remembered, if anybody even saw. And it was not as big a deal as I thought it was. So just try to have fun. You're at school to learn, but also you're going to have a great time.