thanks so much, xx
If you wanna remember things for long time then you have to do lots of practice and something called spaced repetition.
For now have fun, but also explore to see if you can start getting an idea of what you want to do in future.
Year 9 - should be somewhat important, but just stay in top set.
Year 10 and 11 together are very important
Yr 12 and and 13 are super important.
Years 7 to 9 are prepping you for gcses coz you have to drop some subjects. The gcses you do at the end of yr 11 are quite important, especially if you don't do a levels, but even if you do they will help you get work experience and unis, jobs and apprenticeships will look at them.
You drop a few more subjects when to you get to yr 12 and 13,(most studnets do 3 subjects, some do 4). These are very important for uni.
If you wanna get into a study routine once you start yr 9 it wouldnt be a bad idea as you will learn how to study well. But also maybe start to learn some languages or an instrument if you havent already.