When you have a DEP account linked with Jamf Now, you'll see your DEP Devices listed within the DEP section. Any devices in your Apple MDM Server associated with Jamf Now will sync into this DEP Devices section.
You can use the ••• menu next to any device serial number to assign a user to a device. You can also use the ••• menu to preassign a specific Blueprint to a DEP device prior to enrollment.
All DEP Devices will use your Default Enrollment Blueprint unless you specify a different Blueprint. This Default Enrollment Blueprint can be set from the Devices Settings tab at the top of the Devices section of Jamf Now.