You backed into a parked car and it moved but it didnt make a dent in the back of the car so you werent going that fast you werejust backing out of a parking space what kind of damage would there be?

Probably not too much damage, but I always like to be sure, so you can take your car to any local shop and have them check for any damages done to the car. Just tell them you backed into someone, they usually aren't too interested who you hit.