You'd better book your flight and get E-ticket in advance to avoid full booking and enjoy discount, you can check the flight fare on ChinaTravelDepot. You need to change boarding pass yourself at the airport on your travel date.

Checked Baggage Allowances
Passengers holding a economy class adult ticket is entitled to bear the baggage of 20 Kilograms (44 pounds) free of charge
Carry-on Baggage Allowances
Passengers holding a economy class adult ticket is entitled to have one piece of carry-on baggage. Your hand baggage should be less than 5 kilograms (about 11 pounds) in total and no larger than 20×40×55 centimeters (8×16×22 inches).

do we need to confirm the flights? If so, how far in advance?