Your own body has gravity. All atoms have gravity. What made you think there is no gravity on the moon? The interaction between the moon's gravity (1/6 of earth's gravity) and the earth's gravity is what keeps the moon in orbit around the earth
The parking space was reserved in advance - and, no one was capable of stealing it - so, they got to keep it... and, the moon does have gravity - it's surface gravity is about 1/6th that of Earth's. So, that helped...