hey there!
dont stress about it too much! trust me...i just began year 10 too! i know how u feel! it can get a lot but with carefully managing your time in doing the right things will help u get very far....currently im studying from some of my textbooks...(just skimming through and revising anything im unsure of)....and using revision websites like bitesize and sparknotes....also a good idea would be to do some practice papers....you can get some free online ones from www.freeexampapers.com...
i also find that studying with my friends helps me greatly! cos i have like 5 friends that are really close to me and we always study together....i rember better that way cos one of my friends always makes a joke or makes us laff and idk why but in exam i always refer bak to that moment and it reminds me of wat we were learning at the time and what she made fun off lol (dunno if itll help u tho haha)
also i find that the cgp books are REALLLY helpful! the break everything down into such easy to remeber diagrams and notes! its seriously worth checking out.....check out their website...that helps too...
another thing that mite help is (if youre a visual learner like me) is drawing diagrams to help you remember....idk about u but i learn chemistry better when i draw the diagrams...
u could try making rhymes and songs and stuff....it works for some ppl....like i heard that miley cyrus (as much as i dislike) made this song once about the parts of the bones or something which helped her in her exams....check it out on utube lol....
well thats the best advice i can give u....my sister who is in yr 11 is going to do her gcses soon too so we both study together lol....
anyways i hope that helps you!
xx
good luck with your exams!