Si ,nelle due spiagge libere , guardando il mare ,verso sinistra prima del porticciolo turistico, sempre nel rispetto degli altri. Buone vacanze a te e al tuo cane!

Hi there, passeig maritim means sea promenade in catalan and it is the name we give to the streets by the shore. In Barcelona it has a lenght of several kilometers and its plenty of restaurants that mostly are opened for lunch and dinner. spanish opening hours are very large so this is almost never a problem for tourists. closing day for restaurants is normally monday but most of the restaurants in the sea shore are open kind of seven-eleven (would be more like seven-16!). In spain we take lunch arround 14:00 and up to 15 or 16:00 but most places you can start at 13:00 or 13:30. this is nice for tourists as they find restaurants less crowded. Its dificult to have lunch before 13:00 in some restaurants but a lot if them open really soon.

If by enjoying the beach you mean taking a bath, water in january and even in march might be a too cold. Walking by the passeig is nice if weather is fine, I mean sunny. Same way goes the beach.

Existe servicio de tren de cercanias desde Barcelona-Sants a Sitges, con buena frecuencia de horarios, recomiendo paravisitar a primeras horas de la mañana, o la puesta del sol,buenas temperaturas e ideal para fotografiar

Very easy. Take the train from Barcelona Sants or Passeig del Gracia to Sitges. Or from the airport, changing at El Prat de Llobregat. Cheap and trains on the suburban Sitges line are around every 15/20 mins.