The chemistry cgp student guide (not revision guide) is brilliant. The biology one is also good, but I would also recommend the ocr one (that’s if your exam board is ocr of course).
Physics and maths tutor is great for practise questions and past papers.
YouTube wise, Machemguy is brilliant for chemistry. Biorach is brillant for biology.
The website chemguide is also great for chemistry, when you need some more explanation.
I also recommend printing out the specifications and following them closely!
I don’t take history, so I’m not sure of an resources which would be useful. Although I’m sure physics and maths tutor will have some practise questions and past papers.
Hope this helps!