Hmm..first of all don't worry. My answer won't be as detailed as other people's will, since I never went to Middle School. I go to Catholic School, so we have elementary school all the way through, from JK-Grade8. But other than like lockers and some other stuff, I think it should be pretty much the same, so I'll tell you what I have experienced in Grades 6-8..middle school years, cause I just graduated from grade 8. I can't say anything about lockers, unfortunately, since we didn't have lockers, for the reason I just explained. For us, we had to change into gym clothes in front of people. But of course there was a guys changing room and a girls changing room. Just no stalls. But that varies depending on what your school is like. What's the difference...well, I guess from my point of view, it's not too different. You do actually have more teachers for mroe subjects, that's a fact you can't deny. And of course, more homework. Changing your clothes in gym gets more serious. For us, we weren't allowed to participate in gym if we didn't change clothes in our "middle school" years you could call it. You get some pretty cool trips, and even some extended day trips. I'm not sure about your school, but I've heard that even in public schools they have ski/snowboard trips. We had that. And usually, in Grade 8, you have a more-than-one-day trip. That is fun. From my experience, Grade 8 is more different than Grades 6 and 7 combined. Of course we had an extra thing: Confirmation (a religion thing), but in Grade 8, we got so many more privelages, some awesome trips, high-school prep, and so much more. So look forward to Grade 8. Good luck, and wish me luck, I'm starting highschool! :D
Edit: Sorry I forgot about cliches. Well for us, we didn't really have cliches. We had groups, but not based on popularity, but on who was friends with who. There were like groups of ppl who are friends of eachother. Some were more known then others, but no like "Oh I have to be an "it" person". But im not sure about public schools. Well good luck!
Source(s):
My Catholic School Experience: Grades 6-8