What types of cles do middle schools have?

My oldest is 10 and in 5th grade. He will be going to middle school next year. The middle school of about 500. I haven't really gotten much information on things yet, because its only Noovember, but I was just wondering what kind of cles a middle school this size would have for cles. I've heard they have special ed cles, and honors cles, then a lot of other things in between and the cles are either semester or year long. My 10 year old is a little behind and there is a helper in his class all day that helps him and 2 or 3 other kids. He has ADHD. The helper also goes with the kids to lunch recess, and most of the extra stuff. He has a little bit of behavior issues sometimes because of his ADHD. So I was wondering what kind of classes middle schools of about 500 offered like Algebra, Geometry, etc, and all the other sublects. I believe they have homeroom first tihng in the morning, and last thing in the afternoon, and they have 6 class periods a day. And right now, my 10 year old is on a 504 plan(small special education plan), and I was wondering how different middle school will be for him and how will the 504 plan change and he probably will not have an aide next year so how can we make sure he still gets any help he needs?