Is English widely spoken?

Yes, in tourist areas, transit, and most restaurants, English is standard. You won't have trouble getting around.

Yes, keep about 500 HKD in small bills for wet markets and tiny food stalls that don't accept cards or Octopus.

Visiting Hong Kong for the First Time: A Practical Guide

To visit Hong Kong, focus your trip on the MTR transit system and stick to the compact areas of Central, Tsim Sha Tsui, and Mong Kok. You don't need a car; use an Octopus card for all public transport and local small purchases to avoid carrying loose change.

Get an Octopus Card. Purchase a physical Octopus card at the airport MTR customer service desk or add the 'Tourist Octopus' to your Apple Wallet. This card is essential for MTR trains, buses, trams, ferries, and even paying at convenience stores.
Master the MTR. Download the 'MTR Mobile' app. Hong Kong is divided by the harbor; use the red Tsuen Wan line to cross between Kowloon and Hong Kong Island in minutes. Avoid peak hours (8:00 AM–9:30 AM and 5:30 PM–7:00 PM) if you dislike extreme crowds.
Use the Star Ferry. Skip the MTR for the cross-harbor journey at least once. Take the Star Ferry between Tsim Sha Tsui and Central for about 5 HKD; it is the most reliable and scenic way to see the skyline.
Find your food. Eat at 'Cha Chaan Tengs' (local tea restaurants). Look for busy shops where locals are standing or sharing tables; if the turnover is high, the food is fresh.

Is English widely spoken?: Yes, in tourist areas, transit, and most restaurants, English is standard. You won't have trouble getting around.
Do I need cash?: Yes, keep about 500 HKD in small bills for wet markets and tiny food stalls that don't accept cards or Octopus.