Depending what xaming board you have chosen- you need to down load the revision checklist - All maths exams have three paeres1,2 and 3.
Thus, there will be three sheets of checklist for topics with with specific individual sections- e.g- algebra- numbers, sequences etc
Once you have downloaded the checklist for all three units-paper1,2,3- then identify your weakest topics. Then browse the yuo tube- and look for the tpoics you need strenghting. Ask your schhol to give the checklist as an other option. Check with freinds and teachers who help you with maths. Recoomended sites- physics and maths tutor, corbett maths ( has questions and answers), maths coach , Hannah Kettle.