by two seasons u mean literally two seasons right bc there is also book of circus, book of murder etc. I know first season diverged from the manga somewhere and s2 is completely original. the "book of..." series are apparently following the series closely tho. nonetheless, imo you would be better off reading the manga from the start regardless.
Yes. Read/skim the manga's first two arcs (Jack the Ripper and Curry Contest), so you understand what exactly has happened and what hasn't. Season 1 diverged from the manga, and Season 2 is not in the manga at all, and if you continue watching further adaptations, you may be confused, especially given the extra material in Season 1 and Season 2's ending.
Then, watch the third season, Book of Circus. Then watch the two part OVA Book of Murder. Then watch the movie Book of Atlantic. These are all in the manga, and they are all pretty faithful adaptations, given time constraints. Everyone has their own tastes, but most people agree Book of Circus is great, if not the best season.
I say you should read from the beginning if not, read from after season 1 since season 2 is not ata all from the manga
Thanks for all the reply’s, due to what you guys said I’ll probably read from the beginning but also watch the 3rd season since a friend as also said it was really good
I only watched the first 2 seasons of the anime should I just read the manga or finish the last season then read the manga, or should I just read the manga from the beginning?