One word. R͟e͟p͟e͟t͟i͟t͟i͟o͟n͟.
Study one small part at a time, over and over. Ask questions and stay after school. Do research and flash cards. All the help you need is there. You have to do your part and dedicate yourself into your class. There isnt a sufficient way to cram information in when you have a test next day, but next time you should do an little something helpful called, s͟t͟u͟d͟y͟i͟n͟g͟.