General advice re: A Levels
The following links provide useful general guidance about how best to prepare for A Level study
http://blog.snaprevise.co.uk/how-to-prepare-for-a-levels-from-gcses/ Useful advice about the transition from GCSE to A Level
https://archive.org/details/nationalemergencylibrary?tab=about This is a free e-library with loads of resources students can access remotely.
https://www.amazon.co.uk/dp/B06XD29GX2/ref=cm_sw_r_apa_i_NzLGEbGRR8RWG. Head Start to A Level Maths, Biology, Physics and Chemistry currently free on Kindle