How do I edit the dropdown menu (navigation) for the Stores pages?

Hi

How would I edit the defaulted Store Menu nav bar? By default, the menu is labeled as such:

Store
(sub-menus)
Products
Shopping Cart
Order Status

When I go to Appearance-----> Menus I can't edit the Store menu.. It seems to have a defaulted drop down menu.

Where are these files located? And how do I edit this?