I want to go from Pudong international airport, to hotel @ 118 Nan Cang St. By Metro

You can buy the Public Transportation Card at the Line 2 metro station of Pudong Airport. You may buy a card with a deposit of CNY 20 and add value you want. For your reference, from the airport, you can take subway line 2 to Century Avenue Station, then change to line 4 and get off at Nanpu Bridge, leave from the exit 3 and walk for about 600 meters to your hotel.

Thanks a lot for your suggestions. I also wanted to know where can I change my US $ to CNY Pudong international airport?

There are several banks located at Pudong airport and you may change money at one of them. Here is the information:

Pudong Development Bank: between Gate 10 and Gate 12 in International Arrivals area;
Bank of China: between Gate 15 and Gate 16 in International Departures area;
Industrial & Commercial Bank of China: between Gate 12 and Gate 14 in International Departures area;
China Citic Bank: between Gate 4 and Gate 5 in Domestic Departures area.