I'm looking forward to the same trip, but it's Vancouver to Sydney for me
I've flown C3 a NUMBER of times, and it has it's highs and lows... but I'll give you somewhat of a medium here...
You'll be flying their fairly new A330-200. The seating is 2-4-2, which is better than some airline's 3-3-3 seating. GET A WINDOW SEAT. You will enjoy your flight much more if you sit at a window or along one of the sides in the aisle. Show up early, reserve your seat.
You'll be flying Sydney to Auckland (2 to 3 hours, I believe). Auckland to Raratonga (4 hours). Raratonga to Honolulu (6 hours). Honolulu to Vancouver (6 hours). You'll have about an hour and a half at each stop. Bring a book. Actually, bring three books. When you're tired (which you WILL be after you reach Raratonga), time stands still.
Food? Depends which meals you get, and what you like
I've had a few great meals (mind you, I'm one of those weird ones who love airplane food) with C3. Their food isn't horrible... but it's not the BEST. If you like fruit, you'll be happy. Perhaps you should pack a little bit of a snack... just to hold you over if needed.
Service is great. Most crews are really friendly and will gladly help you at the push of the call button. Don't expect to be pampered... but you'll be taken care of.
Some seem to think you're jammed into those seats. It isn't that bad! Unless you're over 6"2... then you might have some problems. I'm a little over 5"11 and haven't had a single problem with their seats. Make sure you get up and walk down the aisle a bit... you'll thank me when you get into YVR
Definately ask one of the FA's if you can get up to the flight deck. I do on every flight and haven't had a single problem. The captain and f/o will be more than happy to have you up there for a chat. Since you're posting here, you obviously have an interest in aviation. Talk to them about it! Ask anything you've got on your mind. They'll be bored as hell sitting there for 22 hours, go up and entertain them!
You should have a good trip. Bring lots to do. The entertainment system is pretty good... you'll see a bunch of movies, without a doubt. If you bring headphones, you'll be able to hear from one side of them. I suggest buying the headphones that are passed out right after departure. ($5 CDN) Again, after about hour 17, you'll thank me
They have music/news/comedy channels on the audio system. The comedy one is great. Updated every season with about 2 hours of new stuff. Fun to listen to. Once. Twice. Over and over, if it suits your fancy.
That's about it. Hope you have a great trip. Let us know how it went!