Hi Yvonne,
Sorry for my late reply, i was travelling and so i didn't read my message until i was back home. Some places that you can't miss in barcelona include the "Park Güell" and "Sagrada Familia", the Gothic quarter is also very nice to take a walk with no destination...just for the sake of walking! don't miss the square of Sant Felip Neri., next to the cathedral ... and if you are thirsty...then head to my favourite bar "El Drapaire" which is in De les Sitges Street... small backstreet parallel to Les Rambles, not far from Catalunya square. Any other info you may need, don't hesitate in asking me. Good luck!