Turn off all faucets, indoors and out, and then check your water meter. If it continues to run, you need to check for a leak. Be sure your hot water heater thermostat isn't set too high. Extremely hot settings waste water and energy when the water has to be cooled with cold water before you can use it. Use a moisture meter to determine when your house plants need a drink.
More plants die from over-watering than from being on the dry side.
Water your lawn early in the morning during the hot months. Much of the water used on the lawn can simply evaporate between the sprinkler and the grass. Use a sprinkler that produces drops of water rather than a fine mist, to avoid evaporation. If you use a soaker hose, turn it so the holes are on the bottom to avoid evaporation. Water slowly for better absorption, and never on windy days.