I'm just going to guess at how you use it since I just got my Babyblue Tamagotchi V3 with Camolauge just yesterday. This is based on what I read from TamaTown.com travel area.
Select the ticket and press the B button. You'll see a plane take off and when the trip is over you'll be given a password. Write the pass word down and take it to TamaTown and enter the code and you will be given another code to enter into your tamagtochi. You'll get a suvanior from your trip.