Barcelona Card vs T-Casual for discountsThere are no discounts with the T-Casual. It is a transport only ticket. In summary for discounts: Barcelona Card gives you discounts on entrance fees for attractions, official Barcelona Turisme souvenirs shop, some restaurants and selected performances.
At each station of the metro and FGC, you can buy tickets either at ticket machines or ticket booths. The machines can also be operated in English. In the bus you can only buy single tickets from the driver. With the tickets bought on the bus you can change to other buses, but not to the metro.
Getting to and from Barcelona AirportRather than buying one of the ticket options mentioned above, you will instead need to purchase a special ticket for the L9 metro line. This will take you directly to both of the airport's terminals, and will cost €4.60 for a one-way ticket.
Bring cash in the foreign currencyWe do not recommend carrying a lot of cash with you while visiting Barcelona. However, it is a good idea to bring a small amount of Euros cash in advance to cover some initial expenses like taxi, meal etc. until you can arrive at a bank or cashpoint to obtain some more money.
The Barcelona Card is a 3-in-1 transport card, museum pass and discount card. Holders of the Barcelona Card enjoy unlimited free travel by public transport, free entry to Barcelona´s best museums, 70+ deals and discounts on visits, tours, entertainment, shopping, dining and nightlife.
The takeaway on getting money in SpainPay everything with your travel debit card and forget about hidden fees. Use your debit card to get most of your money after you arrive in Spain. You can get your first wad of cash from an ATM at your arrival airport.