You will love Spain, just don't tell everybody about our secret treasure.
As for the dictionary, I would recommend you buy one in Spain. Most bilingual pocket dictionary available in the USA are targeted toward the Mexican dialect. If you have to buy one in the USA, then I would recommend the ones made by VOX. Vox is a Spanish publisher, so the translations are more standardized than the ones offered by the popular University of Chicago dictionary.
It is amazing how most of the bilingual dictionaries in the USA, give words like "linda", "valija", and "anteojos" for "bonita", "maleta", and "gafas". The first three words are not currently used in Spain, yet many bilingual dictionaries fail to mention this.
Cheers