I love Barcelona!
Barcelona is so colorful and filled with art that you’re going to need at least a week to really embrace the culture and drink all the sangria you can. It’s the home of Gaudí, Miró, Casas, and so many other artists that come from Catalonia or Barcelona! The mosaics that make up Park Güell are absolutely stunning, La Sagrada Familia is an architect's dream, and the Palau de la Música Catalana is breathtaking! There really aren’t enough words to describe Barcelona.
Barcelona is an artist’s playground, but even if you’re not an artist you can appreciate the city. With Camp Nou, the soccer stadium for Barcelona, so close to the city center you feel the pride of the Barcelonians. Around the city you can find tapas, or finger-foods, that are a nice way to snack and keep moving. You are able to see the beaches from the ports that are close to the city center. And if this hasn’t convinced you yet, remember the paella! They generally come in three variations: fish, chicken/beef, or vegetarian - you have to try some. Then, after the paella, you can binge on churros.
If you really only have a few days, I would make an effort to visit La Sagrada Familia, Park Güell, La Rambla street, Casa Milà, and the ports along the coast. If you have some extra time I’d visit the shops and museums in the center of town. There are some nice museums that highlight the famous artists from Barcelona and even fun ones like the Museum of Illusions or the Big Fun Museum (yes, that’s really its name). I’d make an effort to visit Camp Nou just to appreciate their love of the sport and their players.
There’s always something to do and see in Barcelona which makes it a fun city for families, solo travelers, and students abroad. There is so much history and culture to learn about Spain and especially with the history between Barcelona-Catalonia. They speak Spanish in Barcelona, and I encourage you to speak Spanish, even if it's just 'gracias' or 'por favor'. Manners, appreciation, and an understanding that not everyone speaks English goes a long way when traveling.
Tips:
A phrase I used a lot was ‘¡me gusta Barcelona!’ meaning ‘I like Barcelona!’
I would suggest getting a metrocard for your travels, no matter how long the stay because it really cuts back on travel time.
Flights to and from Barcelona are fairly easy but remember if you’re flying in to come into Barcelona - El Prat (BCN). Some airlines fly into Girona which is about an hour and a half away from the city center.