How do I turn water off to stop leak?

Turn off the Stop vale witch is usually in a cobard or under the stair way

Systems have many isolation points. Look where the water mains enters your property, normally in the kitchen to provide immediate potable water. There should be a stop valve that has a brass handle. That will cut the mains off. The others will stop the flow of hot water.

Hi Those are isolation valves, which will close just the single utility. if have an urgent leak , you May be able to close the water from your pavement outside on front your house. Regards INFINITY SERVICE Luca