Generally most classes have around 20 people. It varies from class to class. Core classes like English tend to be almost if not totally one grade. All classes are about 30-45 minutes in length, depending on the day and schedule. It depends on the teachers and classes that you are taking.
Some teachers are light on homework and others give some every day.
You get 5 minutes in between each class to get ready for and get to the next one. If you are tardy you get a tardy slip and on the fourth time you get a referral and will have to spend three days after-school in detention. If there is some reason that you need to talk to the teacher after class and it takes long enough that you can't get to the next class on time then the teacher will give you a pass to go to the next class so that you won't be penalized for being tardy. All study halls have middle lunch. Class that have lunch after class are music, PE, social studies, English, and art.