So I was on AQA last year but same thing really. So I wrote out all my notes, made flash cards for every long answer question in the last ten years and memorised them over the course of a couple months- this alone helped me to learn all the content. With A-Levels especially biology it’s not even about your knowledge, it’s about being able to write the keywords they so strongly desire. I did an odd mind map or poster on the stuff I found more difficult and came out with an A*. Honestly though the flash cards are a lifesaver- often under appreciated, get your parent/guardian to test you also and you’ll have it down in no time! 😊