So I've just finished my GCSEs and I hope this gives you a bit of advice! I've never taken Geography so I can't comment on that as I went for History instead but I did take Triple Science and PE. Obviously we might not be on the same exam boards but for me a lot of the Biology linked to PE. The triple science courses were hard at times but just make sure to take clear notes from lessons and if you are in the slightest unsure, ask your teacher. They're there to help you and for me, my Physics teacher was a star who would stay behind most days just to make sure that people were on track. Chemistry was the worst exam wise so just make sure that when it comes to revision you have an equal balance of notes as well as reading through past exams because a lot of the time they just recycle the questions. As for PE, I didn't like it too much but my teacher wasn't fantastic so that's probably part of it. Aim to get a good practical grade which will take a lot of pressure off in the exam and learn the mark scheme because the way that the actual exam paper wants you to answer is pretty odd. I'd say make sure to do quite a few past exams for this. Overall, study hard and try your best but don't burn yourself out too soon. I massively stressed about my November mocks and it wasn't good at all. Obviously treat all of your mocks as real exams since it will give you a true indication of how you're doing but most importantly, no-one can say anything less of you so long as you've tried your best. Good luck with your GCSEs! :-)