When Audio Architect first opens, the Offline Design Tab is the ribbon presented, and the Device Toolbox appears on the left and an empty Properties window is at the bottom. The Add Devices box is highlighted.

Selecting one of the buttons in the Offline Design Tab will offer different options in the Venue Explorer as well as bringing up a new Tab specific to that button.
Go Online: Closes the Offline Design tab and opens the Online Operate tab. This will put the application online for system operation.
See the Tools menu HERE.
See the Custom Panels menu here.