Since in the past production has always provided the tickets for the first flight either in the clue envelope, or by instructions in the first clue envelope, I don't see them having the teams scrambling to figure out where in the world is Carmen San Diego Phil Koeghan. They will know that they need to go to a certain airport and go to a certain ticket counter. IIRC, at least one team was shown getting into a llimo leaving their house with the camera crew.
My guess is that the teams were in LA for the pre-Race seclusion period, had their back packs searched for forbidden items, then flew back home with their camera team for the first leg to await the video message for the start of the Race. I would guess the first clue would be with their backpacks, placed their by the camera crew, or in their transportation to the airport, or handed to them by the camera clue off camera. Take your pick.