Quick facts about Barcelona

Currency: Euro (EUR)
Language: Spanish and Catalan
Population: ≈ 1.6 million (Barcelona City); ≈ 5.5 million (Barcelona Metropolitan Area)
Climate: Mediterranean, with hot summers and mild winters
Time Zone: Central European Time (CET), UTC+1
Visa: Spain is part of the Schengen Area. Most EU/EEA/Swiss citizens can enter visa-free, as can visitors from the U.S., Canada, Australia, and several other countries for up to 90 days.
Transportation: Barcelona is served by Barcelona-El Prat Airport (BCN) as well as Girona. Be aware Girona airport is a separate city. If you arrive late and have to take a taxi, it will cost well over €100 to get to the city center.