You will need some Hong Kong dollars for your two-night stay but you could either get these in advance or when you arrive. Hong Kong is an expensive city but there is plenty to see and do that costs little or nothing, and you will have an included tour of the city. I would

You will have all your luggage with you in Hong Kong so it might be worth thinking about what you will need in Hong Kong and storing those things in a bag within your luggage. This would save you having to unpack everything to find a pair of socks!

Both flights are via Hong Kong so you won't be passing through any US airports and won't need an ESTA.

Have a great trip.

Kind regards,

Olly, your editor