Question

Hi.
I have just finished watching the anime and personaly i think it was very good.
Enough talking about opinions let's jump to my question.
As most anime they are made from a manga, but here i got a little bit lost since when i entered the first online manga site (i would buy the paper version but it's hard to get in my country and i'm a brokie) and opened the newest chapter i saw something that was way before the finish of the anime. So i'm wondering is the manga behind or how does it look in this universe. I also heard of light novels? I'm kinda new to the entire anime and manga community so i don't know much. What is the anime based off and if i want to continue with the plot what should i read and where? If someone would be so kind to anwser i would be grateful. Hope you have a good day yall.