I have not studied anything in 11th. What should I do? Like really, I have to clear the NEET in the first attempt, but I am afraid as my 11th was not so good? What should I do now?

No worries . Focus on grade 12 . After boards , revise on 11th grade . You will have good amount of time to revise on 11th . Be confident . When you think you can do it , you will do it .
So past year neet papers will help a bit . Don’t rely on that only .