I think you can visit Ocean Park, Aberdeen, Stanley Market and The Peak on the first day, since they are all located in the southern part of Hong Kong Island, and Ngong Ping and CityGate in the Lantau island for the next day. The transporation for the first day is: since you may take a ferry from Macau, you will board at Hong Kong-Macau ferry terminal at Sheung Wan. Take Hong Kong MTR Island Line to Admiralty, change to Bus 629 to Ocean park, take a taxi to Aberdeen, take Bus 73 to Hong Kong Stanley Market(https://www.travelchinaguide.com/attraction/hongkong/island/stanley.htm), take Bus 6A，6X，66，260 to Central, and then change to Bus 15C to the Peak(https://www.travelchinaguide.com/attraction/hongkong/island/victoria.htm). For the second day, you have to tell me where you will leave for first. the Airport Express Travel Pass can also be booked on line. The official website is: http://www.mtr.com.hk/eng/airport_express/tf_index.html

Thanks Mr. Mark. I think I will give Aberdeen a miss and just hit for Ocean Park and Stanley on the same day :) And thanks for the website too, I have purchased the tickets online. Appreciate the assistance! :D