Hola John!
As I said before, don't worry about the language, we are really used to deal with tourists who doesn't speak a word in spanish, lots of people speak spaninglish and body language would do the rest. Just one thing, don't pretend everybody to speak english, that's something that really annoys us.
For clubs I would recomend you La Terraza or Catwalk. Also Space or Fellini are good options. About bars and restaurants I would suggest you to explore El Born (excellent restaurants, bars, shops and vibe) and las Ramblas and streets around. Most of them look like red light streets but as long as you take care of your wallet you'll be ok.
For touristic activities here is a little modernist tour:
- start visiting "palau de la Música Catalana" a stunning concert hall, if you can visit the inside do it cos it's amazing.
- Then walk up Passeig the Gracia, with three gems of Modernism (two Gaudi buildings)
- Take the tube or a bus to La Sagrada Familia and if you feel strong enough climb up the towers
- Take the tube againg and visit Park Güell and enjoy the views and the place cos it's magic.
John, if you make a search on this site you'll see there's lots of Barcelona advice posts.
Hope you enjoy your stay and don't forget your sunnies and your sun protection
