You should do some extra credit. If your teachers didn't already offer some, then ask. If they see that you're a hard worker, then I'm sure they'll be glad to offer you some extra credit.
Don't be afraid to ask the teacher for help. Raise your hand during class if you have any questions, talk to them after class, or get a tutor.
Use mind mapping. Instead of writing your notes in complete sentences, draw bubbles like you did when you were younger. In the center should be the main concept. Then, the other concepts should branch off of that. So, in the center could be school and then items that branch off of that could be: learning, standardized tests, teachers, students, grades, and etc. Each topic can have things that branch off of them. For example: grades--could also have: curving, favoritism, and extra credit. Everything should be one word or a phrase; you only need what's necessary. This will teach students quality over quantity. Use different colors and draw pictures, so that it will be easier to remember. During the test, students will think to themselves about which color everything was. One student will say, "I remember that I put learning in blue and I made a textbook."