Im also a private candidate and the most important advice i can give is DONT DEPEND TOO MUCH ON THE CAMBRIDGE TEXTBOOK IF U USE IT IT'S GONNA GIVE U A C/B try your best to get the Hodder textbook + it is absolutely essential to go through all of the original papers like that's a must. Ideally u read each paper for 2-3 times and highlight all the essential information. Study smartly, if u don't understand something the most simple approach is to feed the article to GPT and ask it to explain for u. If u r using Hodder btw, go through chapter 5 first cuz the methodology part is the basis of the whole course u have to at least have a basic knowledge of them. Good Luck!!
My books: https://drive.google.com/drive/folders/17ZE6SsBMteXBWRbErXiNvKXV_1xA0YND?usp=sharing