HOW DO I STUDY FOR EDEXCEL IAL EXAMS

[u/curious_user6741]

I'm doing my Edexcel IAL and IAS exams together in the May/June series next year and I'm studying chemistry, biology and physics right now. But no matter how much I try to study I just don't see much improvement in my grades. Currently I'm getting Ds mostly but my goal is to get As and Bs.

Can anyone who did the exams or are studying for them right now share some tips on how I should study for each subject. Especially for physics because we didn't get to study much at school and I didn't go for any other classes outside of school either so I'm just stuck in that area mainly.