The moon takes about a month to orbit the earth, and therefore, that is how long it takes to go through its phases from a light crescent that waxes (light part grows) until it reaches a full moon, and then wanes (light part shrinks) back to a thin crescent and then a new moon (only the dark side of the moon faces from earth, making it invisible at night).

When you see the moon moving across the sky in a single night – from its rising to its setting – you are catching the moon in just a very short window of time (a few hours) during this process that takes a full month! So the change of “shape” of the moon is basically imperceptible in the short time between its rising and setting in a single night. The moon’s “shape” largely looks the same from moonrise to moonset each night and the change can be observed not within a single night, but over multiple nights.

I hope that answered you question adequately!