About the early travel to Hong Kong International Airport

Generally speaking, you need to arrive at the HKIA at least 2 hours in advance before the departure. Thus you'd better to arrive at the HKIA at 07:00.
Taking the airport express train is not convenient for you. You can take bus no.A21 from Pitt Street, Nathan Road to HKIA directly. It takes around 50 mins on the way. The earliest schedule of this bus line is 05:15.

Thanks for the answer man.
I will be staying at hotel on Tung Fong Street. Is it close to Nathan Road for the Bus?
Can you inform the exact bus location?

Thanks

Take Tsuen Wan Line from Yau Ma Tei Station and get off at Tsim Sha Tsi Station, Exit B1. Then get out of the metro station, you can see the Nathan Road directly.