On Cityville Passenger Planes Goal you need to Unload 15 Rome Airlines, if you have some difficulties where or how to find rome airlines.. first there are 2 things you need to know : the passenger terminal is DIFFERENT from the cargo terminal
here are two kind of planes :
CARGO: Paris, Barcelona, Shanghai, Tokyo, London
PASSENGER: Rome, Toronto, New York, Berlin, Rio
If you have all 4 spots occupied by cargo planes you need to buy and staff Airport Terminal Extension and place there new passenger plane (buy in build menu > categoryy goods > tab: planes).
so you must complete the passenger terminal, and place the airport extensions, and fully staff them before you can add passenger planes, once you have done that, you can click on the passenger terminal or passenger plane to view those routes