We got there three days in advance in order to see as much of Barcelona as possible (still not enough time) and we stayed at that same hotel. It is a Disney one with a
DCL desk in the lobby, if you want to check on transportation to the ship, luggage, etc. The staff there was great and helped us book tickets into Parc Gruell. Now, you might check Rick Steves' books on Med. cruise stops, look at all there is to see and prioritize. We booked two activities on the internet, through Trip Advisor, before we flew over...one was a self-guided tour of Gaudi's Familia Sagrada with elevator ride to top of one spire (you walk down). Dan Brown's last book, ORIGIN, takes place in several of Gaudi's structures, La Pedrera (which we walked through) and the cathedral. Read it on the plane over. We walked to both of these buildings from the hotel and the old town (the subway and bus systems are good, too. The other booked tour was of the Old Town (Gothic Quarter) which was great. We took a cab there from Parc Gruell then walked back to our hotel by way of dinner at the 4 Cats restaurant that Picasso visited often (pointed out by guide on the tour). This walking tour included Old Town and Picasso's museum. Parc Gruell is a great place to visit, too...looks like Whoville.
This city is awesome. It was part of our B2B Med./WBTA, so we saved La Rambla for our between day, which worked out great. Again, Rick Steves has videos that show many of the sites...hard to pick which ones to see first or with limited time. Also,
beware of pickpockets...I got nailed in a gift shop across from Parc Gruell...only lost about $20 in day spending money in my cargo pants pocket...I wore a money belt under my shirt with the serious stuff. You might have to come back to Barcelona again to get in everything you want to see...cruise on...