best transport from hong kong airport to HK convention and exhibition centre, 1 expo drive

I'm afraid there is no direct bus taking you from the airport to your destination. You can take the Airport Express Train to Hong kong Station first. Getting out of the station from Exit B2, you can walk to Jardine House, Connaught Road Central to transfer to bus 43X. You need get off at Hong Kong Convention & Exhibition Centre, Harbour Road.
Don't worry! As the Convention$ Exhibition Center is located at Wan Chai, you can easily get a hotel there, such as View MapRenaissance Harbour View Hotel and View MapHarbour View International House.