I booked tickets from Shanghai to new york and from Los Angeles to Shanghai on United Airlines official website. Where can I get a travel route?

I said, have you booked a round-trip ticket? If so, just once. Moreover, if you have good confidence in yourself in your mind, you don't have to take it. You can board the plane with your ID. If you are worried about this, please print it on their official website. There must be. Otherwise, you can ask them to send you an electronic receipt with detailed itinerary information.