VGen and Toyhouse Adoptable

Hi! Im C (30yo/F) Can someone please educate me, give me reccos and suggestions in regards adoptable in VGen and Toyhouse? I don’t wanna do comms yet and I just wanna create and maybe make a passive income while doing so. I wanna create and sell adoptable. Saw some from clock app. Do I need to create just 1 PNG for the OC/Character? Do I need to add different emotions/faces.

Im starting over as an Artist after I stopped drawing due to stuff when I was 18yo. I know its kinda a dumdum inquiry but pls be kind. Thank you!