I can't remember my first few times out of the country. My Dad's a railway man and when I was really little we got decent prices on travel across Europe. As a result, it's something I end up taking for granted. At least I'm aware of that though.
My first time flying was odd though, partially because of a British Airways strike disrupting a great deal of traffic out of Heathrow (where I got a Buzz Lightyear from the Disney shop when they were sold out everywhere else! BUZZ BUZZ BUZZ LIGHTYEAR TO THE RESCUE), even though my Dad and I were only going to Paris. It excited me though, and I was loving learning French to the kid level :) That, and I've always loved Underground/Subway systems and going on one other than London for the first time made me eep. Always loved baguettes too.
I can imagine it's a big step for you to be away for quite a while, so good luck. What exactly are you heading over there for? Make yourself comfy on the flight and don't trust your instincts with the onboard map. Like, flying west to east across Australia for example? Flying over Perth =/= "almost nearly there".