Hong Kong's pretty similar to Singapore with the exception that it has more hills and sea around. The difficult terrain was what contributed to how Hong Kong was built. Residential areas consist of high rise buildings, and in the city areas, there are shops occupying the first and second floors. There's no clear separation between residential and commercial area.
Getting from the airport to the city is easy and fast via the Airport Express. The fare is at HK100 and can be paid for with the Octopus card. The Octopus card should probably be the first thing to buy in Hong Kong. It covers nearly all forms of public transport.
If you want to visit The Peak, you would want to stop at Hong Kong station and walk down to the Central Pier. The bus to take would be 15C at the time of this writing, and it will take you to the Peak Tram station.
It's crowded but the queue moves fast. Once you're on the tram, it's a 45 degrees climb up the hill.
The view of the city is beautiful at night. But this is not the place to catch the city harbour light show, aka Symphony of Light.
There was an advertising signboard at the bottom telling us that houses on this hill cost upwards of $HK20 million. This one probably cost much more.
Dinner's great! They have road side stalls where you can order whatever you want, if you can name them. If you don't speak cantonese, it might be wiser to let the assistant recommend which are the better food. Always ask how much each dish cost. Food in Hong Kong is relatively more expensive than in Singapore. There's a flask of tea and bowl on the table for washing utensils.
All the days in Hong Kong:
Day 1: Looking at Kowloon
Day 2: Visiting the Giant Buddha
Day 3: Ocean City
Day 4: Macau