When you buy your ticket, you'll receive an email with the confirmation/itinerary. You can get a copy through Manage your booking as well as all the information about your ticket. In this section, you can also retrieve your details, add contact information, check-in for your flight, and much more.
On the day of the flight, just identify yourself at the airport with an official document that proves your identity.
If your ticket was issued by a travel agency, please contact them.