Are there any rules for picking up non-hostile creatures?

Grapple rules seem to be geared towards a constant struggle between two or more combatants. But are there any rules around, say, throwing a wounded NPC over your shoulder to bring them to safety, picking up your party member’s trio of pet rats, or having one of the creatures concede during a grapple? For example, what sort of action is it, and does doing so impose any sort of penalties?