Clean with a warm washcloth let it dry and then apply aquaphor. As an alternative Tubby Todd all over ointment
My kids all had sensitive skin... aveeno lotions and bathwash help.
If you still breastfeed or pump, breastmilk does wonders too. I put the milk on my son’s cheek when he had some rash, it went away after a day or two.
Aquaphor