Hi!
In History topics the following are there
Ancient History
Mediaeval History
Modern History
World History
You don't need to mug up anything. It is tough. I'll suggest make a note of important person's who made an impact. Major events. Keep a notebook with you and note down important stuff that will help you while revising.
Hope this helps!
Good luck!
The history subject comes under general knowledge part. so you should study the Indian history ( history of India). It includes everything about people, monuments, empires, acts,places of India etc..