To your questions, Ms. Crystal:
1. Take bus A21 at Airport (Ground Transportaion Centre) Bus Terminus and get off at Middle Road, walk one minutes to your hotel: Bus fare: 33HKD
2. Use Hong Kong MTR: Tsim Sha Tsui - Lai King - Sunny Bay - Disney Special Line to the park, fare: 18HKD
3. Take MTR to Admiralty (8.5HKD for just one stop), then change to Bus 629 to the Ocean Park directly, bus fare: 10.6HKD
4. Walk from Tsim Sha Tsui MTR Station to Tsim Sha Tsui East MTR Station (they have underground passage connected). Take metro one stop to Hung Hom, ticket: 4.5HKD. Then change to East Rail to Lo Wu, ticket fare: 33HKD. Pass the border, you are in Lo Wu district of Shenzhen.
5. Take metro to Sheung Wan (8.5HKD for 3 stops). Go upstairs to find the ferry piers of HK-Macay Ferry Terminal to Macau.
Cheap food: get to Yau Ma Tei area, food in Tsim Sha Tsui, Causeway Bay and Wan Chai area are not expensive