If you receive a monthly water bill from your local water district, then you most likely have a water meter. If you don't get a bill, then you probably don't have your own meter.
If you have a well, you may or may not have a water meter.
In many states (CA, OH, CO, FL, NC, etc.), your water meter is most likely located in a cement/metal pit near/on the street in front of your house. It may also be on a footpath leading to your house. It probably looks something like this:
You will need to lift the lid in order to access your water meter. Click here for instructions on how to lift your lid.
If you live in a colder climate, your water meter is most likely located in your basement. It might be out in the open, under a sink, or in a closet. It will probably look something like this:
If you still can't find your meter, give your local water utility a ring and they will tell you where it's located.