The key to maths is to understand a topic and then practice a lot!
For learning topics id recommend using Corbett maths, Cognito, first class maths, the gcse maths tutor (all on YouTube)
Then once you understand a topic practice a lot! Corbett maths does excellent worksheets which id highly recommend utilising. Cognito also have their site with all the practice questions which is good for explaining solutions!
Once you’ve understood and practiced a topic it’s important you dont forget how to do, this is where consistency comes in. For this Corbett maths actually do 5-a-day questions suited to different grade levels so id recommend those.
Dear god i sound like a Corbett maths advert lol! Would be happy to answer any questions about revising for gcse maths (I got a 9 and am currently tutoring a younger student in gcse maths 🙂 )