parent or guardian?

This is probably because I grew up in the typical nuclear family, but making the parent phone calls today is totally awkward and weird. Am I looking for a mom? A dad? A grandmother? The mom isn't home and the dad is there but he doesn't actually live there. Another mom (I think...?) really doesn't sound like she gives a rat's ass what time school starts. More than a few of the numbers I have are disconnected or just plain wrong. I'm about half way through my calls and the thought of finishing is very discouraging.