Need help (sort of urgent)

In 12th currently and the same classic story with me too... 11th wasted and have already wasted half of 12th

I'll be attempting mht cet in Dec 26 and jee in Jan 26

Haven't done much and need somewhere to start

Too confused on what to do and where to start

(Though I'll appreciate each and every one of yall's advice but please no vague advices like "kuch nhi bs pyqs lga last 5 years ke" cause I genuinely don't have anything to solve them)