Dear Kaylee, I am German and went to Spain for my studies. My advice would be to learn as much Spanish as you can in advance and what helped me to learn the language in only 3 month was NOT going to BCN or Madrid, but to Vigo in Galica. this is not a touristy place at all and people don't speak any other languages than Spanish (and Gallego). I feel that in cities like Madrid and Barcelona are great travel destinations, but the real authentic life is rather in smaller towns and cities. I also read several books about the culture and history to understand more about their behavior.
I would definitely second Ana´s comment about adjusting your day to day structure to be a part of society and I encourage you to try all the different local foods. Spain is so diverse in landscape and food. Go visit Asturias, don't miss out on Galicia (Islas Cies are like the Caribbean's,) go to Sevilla to experience Andalucia and also Granada and Malaga are great, as well as one of the Islands.
Most importantly, enjoy!!!!!!