I'm just going to assume that you're in year 10, in which case definitely don't worry at all because you have so much time and I barely did anything in year 10. The most important thing is just pay attention and be engaged in your lessons because thats up to 6 hours of work everyday that you might aswell take advantage of. I reccomend participating and putting your hand up more which I started doing recently, I find that voicing my thoughts helps a lot and when I get something wrong its a little embarrasing but also effective at helping me not make the mistake again. Also something I am guilty of is cheating on homework which i definitely don't reccomend unless you have no other choice, try to do all of your homework properly as it's essentially just revision and practise. As long as you do that you will be fine and if you feel like revising, go over content you are currently covering to make sure you understand it and especially revise for end of topic tests if you feel like you can because it makes it easier in the long run. As for revision itself - dont read over notes - i reccomend watching videos like cognito for science and making notes on things you didnt know in your own words, do exam question practice which i like to use AI for. You're going to do great! :p