Why do all planets and moons spin?

Your question is very interesting because the answer is that, no, the Moon is not unique. Almost all moons in the Solar System keep one face pointed toward their planet. read more

Planets form from material in this disk, through accretion of smaller particles. In our solar system, the giant gas planets (Jupiter, Saturn, Uranus, and Neptune) spin more rapidly on their axes than the inner planets do and possess most of the system's angular momentum. read more

All known moons. But in theory, there could be a moon orbiting a larger moon, if the large moon was far enough away from the planet. read more