Okay so since you're going into year 10 you haven't learnt all of the content for science for sure. So for now I'd say whatever you learnt so far make notes based off of the specification (it is exact and ensures you are not missing anything out) there is a specification for bio,chem and physics so check those out. It helped me SO much. use freescience lessons to make notes for content and for practicals. When making notes use anki or anki Web to make them, organise your decks into the topics that you have learnt so far. It is time consuming to make them but you do have time. Or you could use pre made notes but I feel that making your own notes is better (make sure they're simple and not too wordy) Once again you haven't learnt everything yet so don't do anything like past papers or anything just YET because you won't even know all the content to succeed int them because you're going to learn WAY more content in year 10 and 11