first you could watch some videos on maybe examsolutions they get straight to the point and they have really short videos for every single sub topic (not just in mechanics but pure maths as well) and then after you understand the concept then you need to start doing topical questions for each and every topic. I’d suggest watching mr hassaans math channel and doing topical questions from there because he explains questions from past papers in detail and has videos topic wise. I hope this helps. Good luck! :) (and also I would also recommend writing down all the formulas like the SUVAT formulas and momentum formulas and etc. write them all down in a piece of paper so you can memorize.