Hi Clive,
The stone steps surrounding the sides of Arena di Verona is where you'll be seated. You can sit anywhere, but the group will be seated together. You can also hire a cushion to sit on if you would feel more comfortable.
Alicia, one of our holiday creators, lived in Italy and visited the arena a couple of times. She mentioned that wherever you sit, the view is very good especially as the steps are elevated.
I hope this helps.
Kindest regards,
Monty