My most worried thing is what if I'm slow at changing and the bell rings ? What do I say to the teacher? I tried looking up stuff even got a book but if you got tips for a rookie TELL ME!! THANKZ!

Each class and teacher will have what they want you to do, normally say you are sorry. But mostly you don't be late, you hurry quickly and make your classes

They usually give you plenty of time to get to your next class. Make sure you have the materials you need before each class. Trust me, you'll get the hang of it. It's pretty simple. They let you practice your locker combinations and ll sorts of stuff, so you will not go in blind. :)

Usually if they no you are going to be late, you can ask for a pass before the bell rings. Depending on the teacher, they might give it to you. But try not to do it too much.