The nearest airports are Santiago de Compostela (55 km), Vigo (64 km), A Coruña (107 km) and Porto (192 km).
In order to get to Catoira from the airport, you should take a taxi/bus to the train station (Santiago, Vigo or A Coruña) and then a regional train to Catoira. You can check train times at http://www.renfe.com/.
If you travel by car, coordinates to get to the Council of Catoira are:
Latitude: 42.66648286421856 (42° 39ʹ 59.34”N)
Longitude: -8.722590502584808 (8° 43ʹ 21.33” W)