I'm so lost. please help me

Okay let me elaborate. I have a few questions first. I’ve read posts where people are using the beds as a background and others are using it as an overlay. Does it matter? And the problem i’m having with it is how to actually code it. For example, I put the background name with overlay name then tried adding my character but I keep getting an error message. I tried doing it the exact same way joseph evans did it in his tutorial but still didn’t work