How to get to mong kok(lodgewood hotel) from the airport? Which card should i purchase?

Hi, take shuttle bus no. A21 at the airport and you can get off at Metropark Hotel Mongkok, Lai Chi Kok Road. Then your hotel is within 219yd away.

How long will you stay in HK? If only for a day, just pay the bus fare onboard, no need to buy a special pass. If you will stay for several days or weeks, I suggest you get an Octopus Card.