I need overlay help please

I need help too. I want a bed overlay. And I also want to do my own. But at the same time I need help I put a car in my backround but I dont know how to layer the car the correct way like i put @overlay shifts to layer 1
and that didnt work then I put @overlay moves to layer 1. It didnt work either. Idk what im doing. And I dont know how to make my characters get inside the car and have the car drive with my characters inside of it the correct way. Please help me.