To perform the basic operations like add, edit, delete customers you can use Customers toolbar.

Or use context menu.

You can perform such basic operations as:

1. "Refresh data"  forces customers list update. It is useful when you're changing connection or have any doubts like is the latest data displayed.

2. "Add customer"  calls blank Edit Customer form, which is used to create a new product.

3. To edit customer you can double click on it or use "Edit customer"  button. It calls Edit Customer form for the customer you've selected . Please see below for options.

4. You can "Delete Customer" from your store . You won't be able to undo delete from store option, unless you've made a database backup. 

5. Or you can send an email to your customer with the help of appropriate button.