How to become a smarter student?

I just finished my junior year of high school and did not do as well as I hoped to. I did not have many extra curricular activities so I studied hard for my classes. Usually, I would only get time to study for my tests the night before and would stay up until an average of 3 am because of other homework as well. However, whenever I studied for AP Physics B, for example, I studied and studied and still did bad in the class. In AP English Lit., my teacher was very hard and that was my first weighted english class ever, so I did not do too well either. I just want some advise on how I can become a better test taker or understand concepts (like physics) better? or even time management? I know this is long, but many thanks.