Spanish food is very diverse depending on the region you are in. While in Spain we have tried many authentic Spanish foods including croquetas, tortilla de patatas, paella, patatas bravas, bocadillo de calamares. Many believe that Spanish food = Mexican food, this is far from the truth and the only thing that they share are Spanish names. Spanish food lacks spice compared to latin food and is way less processed than the food we have in the United States so produce expires more quickly. Another thing that I noticed all over Europe was the boxed, unrefrigerated milk which was very foreign to me and took some time to get used to.
Recently we attended a Flamenco show at a Tablao. Expression in dance and music is one of the main ways that the Spanish were able to express themselves during the reign of Franco so it has heavy roots in Spanish culture. If ever in Spain, you need to see a Flamenco show as it was one of the coolest experiences that I have had in Spain.
Spain has 5 official languages, and you are destined to hear more than just Spanish while in Spain. While I have been in Spain, the majority of the time I have spoken and heard a majority of Spanish, but other regions use different languages such as Catalan or Euskara. In most European countries most people speak enough English to communicate, while in Spain because of Francoist rules, if they were born before 1985, they probably do not speak English because it was banned from being taught in schools. If you have no experience with Spanish and are planning on studying in Spain, it would be best to learn basic conversational Spanish to get by in day to day living.