I included a few things about correct behaviour in class. Can you please check them, too?
1) I should get top marks in all subjects. I should apply myself (fully) when in class. I should get involved in the lessons.
2) I should ask my classmates about next time's homework when I'm absent. I should revise for a day or two before a test (??).
3) I mustn't bully either my classmates or the teacher. I must tell the teacher if a classmate bullies me.
4) What does this sentence mean?
I want to get some qualifications before I leave school.
5) I mustn't cheat during (or in) tests.
I can ask my teacher a question or (for) an explanation or a translation. I musn't prompt a classmate during an oral test.
6) I can get a snack from the vending machines during the break. I can chat with my mates during the break. I can go to the toilet if the teacher gives me permission.
7) I must sit properly (upright?) and take notes during school hours.
8) You get a mark for conduct, too. So you mustn't misbehave in class. If you misbehave, your teacher can reprimand you (in the class register):
9) You mustn't interrupt your teachers when speaking; you musnt' run along the corridor,you musn't drop anything on the floor.
I'd change all those instances of "should" to "must"!!!
2. "review" <~~I think that's what you mean, right? Revising is when you go over a rough draft of a paper and do some reorganizing and rewriting.
4. I take this sentence to mean that someone wants to get some good, specific training in a particular area -- and a certificate or diploma to prove he/she has learned what is needed to qualify for work in that field.
9. You mustn't interrupt your teachers when they are speaking.
You mustn't run along the corridor.
You musn't drop anything on the floor ... or if you do, you must pick it up.
All else looks good.