Why doesn't the moon rotate?

The Moon, rotates--at the same speed as it orbits the Earth. So, in the 27.32 days it takes the Moon to go around Earth, the Moon also spins about its axis one full revolution. That's why we always see the same "face" of the Moon.

The far side of the moon (which we never see) is sometimes called the dark side of the moon. That side gets plenty of sunlight, about as much as the near side. But, it would be slightly darker there, as it never gets light reflecting off the earth.