The Jujutsu Kaisen manga has been running for several years and has a considerable number of chapters. But the exact length can vary depending on how you measure it, like by chapter count or total story arcs.
I'm not sure exactly, but as of now, there are quite a few volumes and chapters. You might want to check reliable manga databases or official sources for the most accurate count.
You can start from the chapter that picks up right where the movie ends. Usually, you can find this information in fan discussions or on manga-related forums.
The Jujutsu Kaisen manga is indeed ending. It's been a great run, but all good things must come to an end. The final chapters are bringing closure to the characters and story arcs.