The first thing you should do when arriving at the airport is check in for your flight, check in your baggage and receive your boarding pass. If your itinerary includes at least one international flight you should arrive at the ticket counter at least three hours prior to your flight's scheduled departure time in order to have your passports verified, to check luggage, and to receive your boarding pass.
Check-in closes between 60 and 120 minutes before flight departure, depending on the departure city as well as the destination city. Please check with your airline to verify check-in requirements. Alternatively, you can check in online free of charge on your computer, tablet or smart phone 36-24 hours before departure (depending on the airline).