Day 1 - Landed in Barcelona - At the airport follow signs for AEROBUS that can take you to the city directly! Either terminal 1 or 2. I was able to buy tickets online by searching for Barcelona train tickets, super easy. They just scanned the ticket when I got on the bus, it was like 10 Eu roundtrip. Took the last stop to Placa Catalonia - it was a minute from the hotel - H10 Metropolitan 4 Sup. It is a pricey hotel (250$ a night), but this was our splurge for the entire trip, so worth it! There were other options for AirBnb's and cheaper hotels, but this was right in the center and even though it was pricey, we ended up not needing a car, not did we need to spend a lot on cabs since everything is walking distance. So if you think about it, you can get a cheaper hotel farther away, but spend a lot on transportation, so in the end, it ends up being the same price.
Day 2 - Visited Park Guell - bought tickets online to reserve entrance since it's limited. Buy at least one day in advance. I bought through Booking.com, or you can buy on-site or on local websites. Park Guell has amazing views of the city and is often used on postcards to represent Barcelona, a must! For food throughout the day, Yelp was my go-to. I searched for breakfast, lunch, etc, and just went with the flow. So many restaurants to choose from, so you will never be stuck with nowhere to go.
Day 3 - Visited Casa Batilo (buy tix online by searching). Very artsy, beautiful to walk around. Spent the day walking around and exploring random parts of the city. Went by the beach, rented bicycles on the street (get the APP - I asked a local at a grocery store what the APP was called)
Day 4 - Ate breakfast, went to the airport
Favorite Restaurants in Barcelona:
La Bodegueta (tapas)
Petrixol Churreria (amazing desserts!)
Bodega La Tinaja
Tapeo (great for dinner)