1. First of all, Barcelona's public transport is really convenient, especially the T10 (9.8 Euros) fare is cheap and good. One Euro can go from the airport (R2 Aeroport) to the urban area (Barcelona Sants Basse Main Railway Station), which is much cheaper than taking a bus. If planned well, you can transfer to tram, bus or metro within 75 minutes free of charge. Each ticket will show how many times you have left. Don't remember by yourself.