Exe Plaza Catalunya (128 €). Perfect location, modern style, good reviews. To get there take a bus A2/A1 directly to plaza Catalunya (5€ pp) or taxi from the airport (30€). Leave your bags at the hotel.
Ome Bistro. Breakfast at Ome Bistro (13 minutes by foot) (12€ pp approx.) Take a walk to the Eixample district to enjoy the architecture, head to Passeig de Gracia, where all the shops are located, do not forget to take a look at the two houses designed by Gaudi (Casa Batlló and Casa Milà), visit is possible (30€ pp each house). In my opinion Casa Batlló is better
Have a lunch in Vinitus, the best restaurant with tapas, reservation is not possible, you will have to wait in queue for 10—15 min (20€ pp) or Cerveseria Catalana.
Check in at the hotel
Visit one of the terraces from the list:Alaire Terrace Bar, The One Barcelona,Terraza Pulitzer Barcelona (glass of wine 5€, cocktail 12€).
Dinner in Casa Lolea (reservation required) (30€ pp) or Elsa y Fred (reservation required) (30€ pp) , both restaurants are located in Barrio Gotico, which is very different from everything you saw in Barcelona before.
After the dinner go to local bars : Zona d’Ombre , Bar Brutal (a little more luxury), Bodega del Born
Brunch at Brunch&Cake by the sea or Makamaka (reservation required for both) (20€ pp)/ or brunch on the terrace of Kimpton Vividora (40€ pp, dj, unlimited food and drinks).
Take a walk along the seafront, visit the Barceloneta neighbourhood.
Lunch at Escrito or Can Fisher with paella (reservation required for both) (30€ pp).
On the way back to the hotel, spend some time at Parc de la Ciutadell or visit the Vermouth festival on Passeig de Joan de Borbo (if available).
Dinner at Palo Verde, Tartareria or Tunateca (reservation required for all) (40€ pp).