How do I go about relearning biology a level content?

I have sat biology a level in 2019 I want to resit it in 2021 I got a B the first time round I would like to get a better grade the 2nd time round. I don't have any of my old textbooks or anything. I did edexcel B, where do I start and how do I go about doing this successfully?

You could start by looking through the specification and see how much you can actually remember from when you sat the A level.
I would recommend getting a textbook or revision guide to help you learn. Do you have any of your notes from A level