I am not completely sure about your first question, so I will start from the second one:
Local Guides program is related to your Google account (gmail).
What do you mean with location?
Do you mean your location as a Local Guide (https://maps.google.com/localguides/home/settings). Of course you can change it, but you can have only one. This location can help Google to identify if you are elegible to receive promotions, or invitation to events, that are related to specific areas
Do you mean your home location, as shown in “your places” in Google Maps menu? In your “places” you can add, and quickly recall, all the places that you want to add