By Plane:
From El Prat Barcelona Airport:
From the taxi you can take a taxi (EUR 30 approx), the Aerobus or the train.

Bus: Take the Aerobus and get off at Plaça Catalunya (last stop). From here you can take the metro from Urquinaona (the other side of El Corte Ingles) and get off at Barceloneta and then walk 10 minutes.

Train: Take the train to Passeig de Gracia where you can change for the metro L4 (yellow) and get of at Barceloneta.