We ate lunch at a small restaurant called Aitor recommended by our Barcelona Day Tours guide very close to Sagrada Familia. They had a large variety of tapas on toothpicks you could see and select as well as Basque specialties. At the end of your meal they count your toothpicks and charge you accordingly. They spoke English. I took a picture outside the restaurant (facing the church where you will enter and go through security with your timed tickets walk to the right around the church and turn right onto a side street where you will almost immediately find the restaurant) so remember the name and just googled it. There are lots of reviews and the directions online. Our Sagrada visit was at 2:15 and we had more than enough time for lunch after our morning tour.
There were plenty of taxis outside Sagrada and we took one back to our hotel, picked up our stored luggage, and got back into the cab for the ride to our ship. There is a metro station at Sagrada Familia also but the taxi didn't cost a lot and with our luggage it was much more convenient.