Looking through Black Butler anime, but where do I have to go on manga?

I saw all seasons Black Butler on Netflix & realized it was over. Now I've heard that a lot is different in the manga, except the beginning, & the second season is just a "spare end". So I want to read the manga, but since I know the beginning, I would like to know which band I should continue on. Has anyone the same experience & can recommend a good job?

Best from volume 1.

Manga and anime are in my opinion completely twisted. I was also very surprised at first. That's why at volume 1.