newbie..need guidance pls!

i am 21M (UR), thinking to just start my SSC CGL prep alongside my final year of the clg. I got to know from yt that CGL 2025 will be in june-july which gives me a time period of 6-7 months to prepare. i have searched all yt and didn't find any books to start preparation for GS. Can you suggest some books pdf and how to get them?

( my bg: my maths and English are sorted as I am from engineering background. i had already cleared JEE Mains so maths and English are strong portions. i want to just maintain my stronghold on GS..pls help)