The official language of Spain is Spanish ('Español') also known as 'Castellano'. However in some parts of Spain, Spanish coexists with languages native to some of the regions: Catalonian (catalá) in Cataluña, Galego in Galicia, Euskera in the Basque Country and Mallorquín in the Balearic Islands.
The Instituto Cervantes is the public institution responsible of promoting Spanish language and culture accross the world. It is the Spanish equivalent to the British Council or the Goethe Institut. It has delegations in many important cities in the world.
Foreign languages are spoken on a reduced scale compared to other European countries. The generation that grew under Franco's regime (franco died in 1975) never learned much about foreign languages (if they did at all). Youngsters and young professionals in cities know a bit more, but it is unusual to find good English speakers. French is the second most spoken foreign language, followed by Italian. Few Spanish speak Portuguese, though Portugal is their closest neighbour. Cash machines in banks have an option to provide services in several languages. Hotel staff usally speak English and/or French. Otherwise it is easy to pick up the basics of Spanish.