Your ticket states that you leave from EZE and arrive in GRU, then you have to get to CGH from where your flight to BPS departs. And you are totally lost.
In World-Airport-Codes you will find a complete listing of airport codes throughout the world. You can consult them by country name (Brazil), by country abbreviation (BR), by city name (Porto Alegre), by airport name (Congonhas) or by airport code (GRU).
For a quick check, American Airlines has a useful and simple City / Airport Lookup tool.