I’m in y12 studying OCR A Physics.
I’d recommend starting by using a RAG sheet to find your weakest topics. Relearn content through YouTube videos, textbook, and savemyexams notes (if you use incognito mode you can get them for free).
For revision material PMT is quite good, plenty of exam style questions. For mechanics, you can do the PMT solution banks meant for A Level Maths. The Online Physics Tutor is also quite good for questions.
If you’re still confused on a topic or question ask your teacher, they’re there to help you!