The main international airport in Argentina is Ministro Pistarini, known as Ezeiza due to its location, situated 45 minutes away from Buenos Aires downtown. If you are planning to visit Argentina, you should look for flights heading to Buenos Aires.
Buenos Aires has a domestic airport as well, called Jorge Newberry, but known as Aeroparque, located in the city of Buenos Aires, 20 minutes from downtown. From this airport, you can take a flight to every main tourist destination in Argentina.
So, if you want to travel around Argentina, you can get your flight to Buenos Aires, and once in Buenos Aires, you can book any Argentina Tours departing from Buenos Aires Aeroparque airport.
Buenos Aires is located in the center of Argentina. From there, you can fly south to Patagonia, or north to Iguazu Falls or Salta. If you want to fly from any location in Patagonia to North Argentina, you will have to connect a flight in Buenos Aires, and the same the other way round.
Therefore, when planning your itinerary around Argentina, it is good to divide the trip into two sub-itineraries: North and South. For example, if you want to visit Iguazu Falls and then the northwest of Argentina, you can fly from Buenos Aires to Puerto Iguazu and then a second direct flight from Puerto Iguazu to Salta with Aerolineas Argentinas. From Salta, you can return to Buenos Aires, or you can make another stop in Mendoza.