1) cute, adorable, lovable, cuddly.
Generally conveying the sort of maternal emotion that a mother would feel towards a baby, and primarily used by teenage girls to refer to something small and baby-like to which they feel affection.
2) Said (or "squealed" is a more accurate word) when the speaker feels the affection described by noony(1) and wants to vocalise this affection. Once again, primarily used by teenage girls.
Omg!!! Did you see those puppy's little legs? They were so noony!!!