It's easy to check in for your Air China flight at the airport or online. Both options are free.
Check-in at the airport
Check-in counters at the airport open 3 hours before scheduled departure and close 1 hour before departure.
Air China also offers self-check-in kiosks at many airports for both boarding pass printing and baggage check-in.
Online check-in
Online check-in times vary greatly by destination, with some places allowing 12 hours, others up to 36 hours before departure.
A detailed list of destinations can be found at https://www.airchina.de/international-list and a direct check-in page can be found at airchina.com/check-in.