You should configure first a web site. Then drag n drop the Store Locator widget from the OCA/Geopspatial section.

.. figure:: ./static/description/snippet.png

You can the configure the maximum number of results you want to display before to force your user to filter results.

.. figure:: ./static/description/snippet_configuration.png

Then go to 'Contact' app and add some store type address to your contacts and add them some tags.