Diagnosis
Yeah, this one's common on first setup. The robot is running in a low-intelligence mode because it hasn't completed its initial smart mapping run. It can't use its camera for navigation until that's done.
How to Fix It
You need to let it do a dedicated mapping run. In the iRobot app, make sure you've created a new floor plan. Select "Mapping Run" from the cleaning options. Clear the floors as much as possible, turn on lots of lights, and let it run until it autonomously returns to the base. This can take over an hour. Don't interrupt it.
If That Didn't Work
The protective film over the camera lens might still be on. Check the top of the robot for a clear plastic sticker and peel it off. Also, ensure the robot's front bumper isn't stuck in a depressed position; give it a few firm taps to make sure it springs back freely.
Heads Up
During the mapping run, keep pets and kids away. If it's interrupted, the map gets corrupted and you'll likely have to delete it and start over, which is a pain.