Most homes have a water line coming out of the ground going into the house. If you have one you have probably noticed a shut off valve appears. By turning that valve off all water inside of home should be discontinued. Individual kitchen sink or lavatory faucet fixtures have cutoffs underneath the cabinets. A hot and cold supply line by turning the handles clockwise you will be able to turn off water. Most water heaters have a cutoff above water heater if your water heater is leaking turn off that valve then open a faucet anywhere in the house on the hot water side releasing the pressure inside water heater tank. If none of the above shut offs work you can always call your city water dept tell them you have an emergency water problem they will dispatch a technician and turn your water off at the meter for free. This is when you call American Construction and Plumbing 24 hours a day 7 days a week.