We’ve started with a pillow under his bottom sheet to get him used to sleeping on one. He’s not ready for his duvet yet but we get him to try with one for his nap
My boy has a toddler pillow but no quilt, will give him one in winter though maybe. He’s in a summer tog bag atm x
My 14month old sleep with a pillow like me the same and he has for a while but sometimes he don’t sleep on it as he moves in night x