First of all don’t panic.
If you are in a coaching institute then try to cover what is taught in class on the very same day.
If not,
Then make small portions to complete per week. And yeah completion doesn’t mean just reading through the lines of the book but it includes practice of mcqs too. That’s the reason why I am asking you to target short portions for completion per week so that you can do ample amount of practice too.
Finally keep a habit of going through the previous year papers as it will give you a hell lot of idea about the important topics that you need to put extra emphasis on and it will make you a lot more prepared for neet.