and in terms of starting revision, I started really early in year 10 and then kind of got worse in year 11 and then when my GCSEs were coming up it was so surreal, but I couldn't do them bc of lockdown anyway. my advice would be don't stress about revision in year 10 (apart from mocks, definitely revise for them) bit make sure you understand everything, that is vital and that is something I didn't do especially in chemistry, I had the mindset "I'll figure it out when I'm revising in year 11" and that's the wrong mindset to have. if you keep your knowledge up throughout year 10, I'm year 11 you can focus on things like examiner reports and exam technique, which is very important