Ferry from HKIA to Shekou, Shenzhen on 2/18/2019 at 21:20 depart. Ticket to buy at HKIA counter?

I arrive in HKIA on 2/18/2019 at 20:20 via UA# 869. I have my luggage w/ me. I want to catch
the 21:20 Ferry from HKIA to Shekou, Shenzhen. Do I buy the ticket at the Ferry counter at
HKIA on that day 2/18/2019? Does the Ferry schedule on 2/18/2019 has the depart time at 21:20
and 21:45 from HKIA as published. At Shekou, do they have taxi available to go to the hotel in Shenzhen?

Many thanks! NHK from California, USA