Hello,

there is no important. Your syllabus is important and you have to cover all as much as you can. No one knows from which part question will come.

if you think making less effort you can cover then it is impossible. you will get confused in the exam hall. so take your time start from easy chapter then go to hard chapters. solve examples then go to excercise. if you get any doubt then ask your friends. there are online videos whom you can watch for easy learning.

There is no  shortcut as education is for learning. if you look for important you will miss the details which are important.

Hope it helps!