i would go over any gcse content covered in year 9 (if u did) and make flashcards of every single thing you've learnt so far in all subjects from ur specs and just every day, do ur homework and make flashcards on the topic covered in class that day. make sure that u use more than just your class notes, try using info from bbc bitesize, ur textbook and the spec for ur course and make sure u mix all the information and put it in ur own words so its easier to remember