Well, depending on how much time you have and interest in history, i recommend you go to Old San Juan. There you have many museums, old Spanish architecture, restaurants, bars, etc.
Food is definitely a very important part of our culture. I sugest you try mofongo with seafood or chicken.
For surfing you can go to El Escambron which is at Old San Juan as well. Ocean Park is more for kite surfing. The best surfing beaches are on the east/west coast (Luquillo, Rincon, Aguadilla). about 7 years ago