First time flyer going to Australia. What do we need to know?

[snozzlemaid]

Ds is 20 and is off to Sydney with a friend to meet a couple of other friends who have been working out there.
He has never flown before (and neither have I) so would be great to hear anyone's tips or essential things we might not be aware of
He has insurance and we know he needs a visa.
What's the best way to pay for things there? I'm guessing some cash and his debit card. Is a prepaid card a good idea?
His friend, who has booked the flights, has flown before and sounds like an organiser so I'm hoping he'll tell ds all he needs to know.
Stop off is Hong Kong so I suppose they'll need currency for there as well.

I never had issue anywhere in Australia. Never had a failed coverage. Telstra on the other hand makes news for outage several times a year.

Once you leave the main cities and even the minor ones, nobody has coverage , you need a satellite phone if you go in the far outback.

In hongkong and singapore, the airport is so big with massive food court and sitting everywhere you don't really need to buy lounge access and internet is free too.

Be aware in Hongkong there are 2 security checks. One in the transit area with the usual metal detector and the second one right before the doors of the plane when they ask you to open the bags and take away all liquids again, even if you just bought it in the departure hall. Long queues form at these security checks. Yes to food no to drinks.

Bit late, but best way to get money would be a Halifax Clarity card. Getting it as an additional card on your account (if you trust him and he is sensible) can be useful for emergencies.

Scan all documents and email them to himself.

This is one of those times I feel like I have failed as a parent by not preparing him in life for travelling

Everyone has to do things for the first time, the main thing is not being scared to ask for help.

Also, knowing where your bags will end up is sometimes not trivial. The only person who knows for sure is the person at check in who prints the baggage tag.

Spicy Thanks. Dropped him at train station this morning so he's on his way.
I feel better now he's gone. I don't worry so much now there's nothing I can do.
I'm sure he's going to have a fantastic time.

He'll have a great time. Sydney is a fantastic city. I'm slightly biased, but it is one of the nicest cities I have ever had the pleasure of spending time in.