Navigate to Manage > Companies to see a list of all Customers, Vendors, Leads, Owners, and Others in your Aero Account. If your Aero account is linked to your QBO account, the Customers will include all the Customers you had listed in your QBO account.
When you first open this screen, the list defaults to 50 Companies at a time and is sorted by Type. You can choose to see anywhere from 5 to 100 at a time and use the sort and filter features to see this screen exactly the way you want to. You can also change which columns you see. When you have this screen set up the way you like, click the Make Sticky button and the Manage Companies screen will load exactly the same way every time you come to it.
To add a new company, click the dropdown menu next to the Manage Companies screen title and choose Add Company.