On the Field Option of the Address field, you have the regular settings for label, description, and required. Also, when you check the required option, you can edit the required message for each subfield of the Address field.
In the Advanced Options, you can see the edit option for each subfield. To change the sub-labels, click on the edition option or simply click on the subfield name.
You also have the option to show only certain address fields from settings. By default all address fields are displayed, if you want to remove certain fields, check the checkbox indicated in the above figure.