You can certainly add more than two locations. You'll do create them in your Square Dashboard.

Our support article has the steps needed, but I've copied the info below:

"To create your first location, visit Business Information in your online Square Dashboard and click New Location. If you have multiple locations and would like to add another, go to Locations in your online Dashboard and click Create Location. Add the following information about each location:

• Address
• Business hours
• Bank account or deposit tag (to differentiate deposits by location)
• Contact information
• Item library (if you want to match the item library from another location)"