Every fingering that fits a hand
x30000
open
x30400
easy · no 5
x30500
easy · no 5
x30430
easy · no 5
x30450
easy · no 5
What is true of it
Cmaj9 is C, E, G, B and D — 1, 3, 5, 7 and 9 counted from C.
On an instrument that cannot reach all 5, the 5 and 1 go first, in that order.
The easiest of the 5 fingerings below is x30000: one finger, held at the 3rd fret.
1 of them use open strings, which is what makes a shape quiet to change to.
1 string stays silent.
Where its notes are on the neck
The brass dots are C, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
Cmaj9/E
030000
Cmaj9/G
330000
Cmaj9/B
x20000
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.