It doesn't.
Whenever we send a ship to the moon it spends time in orbit, circling the moon. While it is in orbit, it is a 'moon' or satellite to our moon. The earth revolves around the sun, the moon revolves...
the moon has 12 moons of its own, and they rotate at the speed of Jupiter
No. Mainly becuase the moon's gravity is not large enough to attract other satellites (other moons) around it
Yes it can. If an object small enough to get caught in its gravity and orbit the moon does get caught then yes it can have a moon.