I saw this the other day, many parts of the US are discovering what happens when the temperature drops, and the homes hadn't been planned for that.
For plumbing on outside walls, open the cabinet doors, allowing room heat all the wall to the exterior wall, to keep those pipes from freezing.
Remove hoses from outside faucets and cover them.
Find the main shutoff for the home and tell the rest of the family where it is.
For faucets on outside walls, you can try letting them drip some.
The hot water supply lines will freeze first.