If you're studying for something other than a standardized test (see Jponbac's answer for that) then you study by using your notes. You should be writing down all of the important points your teacher goes over in class, keeping your graded homework papers, and taking practice tests from your textbook. That way, everything important is in your notes and you don't have to try to read the textbook again the night before an exam.You don't really need a tutor unless you're doing really poorly or really struggling to understand the material. In that case, ask your teacher how to find a good tutor - there are usually people in your community who will help with that.