First things first Volume of a rectangular prisim: lwh~ length*width*height of the prisim.
Plug in the mumbers you have doesnt matter what goes where.
9*19*12
9*19=171*12= 2,052in CUBED. volume is always cubed. a way to remember that is volume you're finding the 3d shape. cubed is a 3 and 3d obviously has a 3 surface area is squared you are finding the flat 2d surface squared is a 2 and 2d is obv a 2.