Time and price to apply the 144h visa

Hi, I wonder about the process at the Baiyun Airport. We will arrive from Bangkok 5 nov. 10pm then leave for Singapore 10nov. How long will the process be at the counter when we have our passport, ticket and arrival card ready? Is there any fee to pay?
I also a bit not sure about the departure ticket from Guangzhou, how do we get airfare tickets with assigned seats if the departure several days away?

Thank you in advance!