The Mandalorian and Grogu, in order
To watch The Mandalorian's story in order, start with The Mandalorian: Season 1, then The Mandalorian: Season 2 and The Book of Boba Fett. That's 5 out so far, about 25 hours, ending with The Mandalorian and Grogu.
Din Djarin and Grogu's story runs through more than The Mandalorian. The Book of Boba Fett fits between its second and third seasons, and it matters for what comes next.
Updated
The Mandalorian's story in order
The Mandalorian: Season 1
A bounty hunter finds a child, and decides to protect him.
The Mandalorian: Season 2
Din looks for Grogu's people, the Jedi.
The Book of Boba Fett
Chapters 5 to 7 bring Din and Grogu back together.
The Mandalorian: Season 3
Din seeks redemption on Mandalore.
The Mandalorian and Grogu
Din and Grogu's first film.
Questions
What order should I watch The Mandalorian's story in?
Start with The Mandalorian: Season 1, then The Mandalorian: Season 2 and The Book of Boba Fett, and follow the list above: 5 in all, ending with The Mandalorian and Grogu.
How long does it take to watch all of The Mandalorian's story?
About 25 hours for the 5 out so far.
Do I need to watch The Book of Boba Fett before Mandalorian Season 3?
Yes. Chapters 5 to 7 are practically Mandalorian episodes, and Season 3 opens straight after them.
Watch The Mandalorian's story with Chronologica
Make a plan of just The Mandalorian's story, mark them off as you go and always know what's next. No account needed.