To minimize damage from a water leak, learn now how to shut off the water to your house. Water to a specific sink or toilet can be turned off by turning the water valve under the toilet or sink clockwise. If you're not sure which direction to turn the valve, remember the saying "righty tighty, lefty loosey"-turning the valve to the right closes it and turning it to the left opens it.
It's also a good idea to purchase a water meter key at a hardware store, keep it in a handy place, and know how to use it to open and lift the meter plate to shut off the main water valve to your home. Water meters usually are located in the front yard.