I did my English GCSE in 2019. I got a 3 for my mocks but ended up getting a 8 for my actual exams with close to no revision. I did make sure that I know how to answer Section B properly, if I remember correctly. I think it was 40 marks for section A and 40 for section B. Make sure you get most of the marks in section B and you should be fine. Read books, so that you can write more easily and have a larger range of words sophisticated words. Know your language techniques, list them at the start of the exam and check off each one you've used.