I wouldn't really be worried. I'm sure your teachers will be lenient with you being late to class for the first couple days until you get used to the school and where your classes are located. If you don't know what lunch you're in I suggest you go to the main offence or guidance or whatever to check your shedule and see what lunch you're in so you don't miss it. Just keep your head up, all the other freshman are probably nervous as well. :]