GCSE Maths resit in a month

Hello!

I just got my timetable for my math resit and my first exam is in under 2 months on November 3rd. I need to get a 7 and I originally got a 4. I was meant to resit it in July but it got cancelled and now I’m taking a gap year to resit.

Is there any advice you can give me. How can I effectively revise this subject. I’m not terrible in maths and with some proper revisionist can do it but I don’t know how to revise independently. Doing a btec I never really had to revise or even do work outside of the classroom so I really need some advice.

I still have my higher cgp book from secondary which I’m using. Is there anything I should invest in, any websites? I’m doing past papers and can’t even do the first question on some.

Please help.