You look on you ticket to see that you're on the Grand Avenue Limited. This route will take you all the way into downtown Phoenix. Looking at street signs confirms that you are on Grand Avenue. It will take a while to get to Phoenix, though. It is your call if you want to stay on the route for the entire time or get off sooner.

In her haste to vacate her previous seat, the woman formerly sitting next to you left her newspaper on her seat.