starting sbi po prep now, need your guidance.

is it too late to start? i'd really appreciate some guidance on how to go about it. i'm a cat aspirant so my basics are mostly covered. which youtube channels are the best for sbi po prep? also, what mocks should I buy, when should i start taking them, and lastly whats the best way to cover the syllabus in a structured and efficient manner from this point? i know the competition is tough and i don't really have much time but i'm ready to give my all. any tips or advice would mean a lot.