Take care when walking from the Rosemont station to Giordano's and back. There are sidewalks, but the streets are wide and the traffic is awful and people won't be looking out for pedestrians.
Also keep in mind that they open at 11, but these pies do take a while to bake. I would maybe call the day before and talk to the manager, see if they could put your pizza in the oven a little early, so that it can be ready when you arrive.