HK airport transfer to Shekou overnight

Hello,
We, a party of 10 will arrive by an Air New Zealand flight operated by Cathay Pacific, will arrive at 9.30 pm. There will be no ferry anymore. We will stay overnight at hotel near airport and take the ferry to Shekou in the morning.
Where is the pier? When should we buy the tickets and check the How long will us to be at the embarking counter?
Thank you for your response.
Regards.
Eliane