When you arrive at the Hong Kong Airport, you can use your UnionPay debit card to get Hong Kong dollars from the Bank of China teller machine there. This is the best way. There are also currency exchange shops at Hong Kong Airport, but the exchange rates are not as good as those at UnionPay tellers.

UnionPay debit cards can be used in places in Hong Kong that generally accept credit cards. Transfer via mobile phone should not be possible. It should be noted that many small shops only accept cash, and many will accept RMB, but the exchange rate of RMB to Hong Kong dollars will not be good.

From Hong Kong International Airport to Yuen Long, you can take the airport bus A36 to Yuen Long. The journey takes 60 minutes and costs HKD 27.70.

Ordinary bus? E34B? to Yuen Long, the journey takes 70 minutes and costs HK$13.90.

Metro: Take the Airport Express to Tsing Yi Station, transfer to the Tung Chung Line to Nam Cheong Station, then transfer to the West Rail Line to Yuen Long Station.

Taxi: 35 kilometers, 30 minutes, about HKD 300, and there is a charge for each piece of luggage.

Hong Kong buses only accept Hong Kong dollars. Passengers pay coins individually and do not know change.

You should consider buying an "Octopus" card at Hong Kong Airport. This is an electronic wallet that allows you to pay with just a tap. You don’t need to constantly pay attention to whether you have enough change with it. Using an Octopus to take buses and subways is much more convenient and saves time, and Octopus can be used in most restaurants and shops in Hong Kong.