While each of you may have a different approach, there are smart ways to study that are useful for everyone. Plan study sessions of about one hour either in school study times or after school. Ask one another difficult questions and review multiple choice questions.
Some people dream of accomplishing great things. Others stay awake and make it happen.
Each subject has a detailed syllabus which is the best guide for both study and exams. Use it to make detailed notes on every dot point in the content section. Textbooks do not always present the information in the same way as the syllabus. So use textbooks and other references to prepare your detailed notes.