Where's my passport?

It has been soon a year since my last trip outside Sweden's borders and a lot has happened since then! I've moved about 160km away from home to study at a university to become a biomedical scientist. Travelling hasn't been so easy because of the lack of time and money, but my second semester is finally coming to it's end and I'm packing my bags and search for my passport once again.

My mother and I try to make a trip abroad every year, just the two of us and usually a capital city in Europe. We've been to Tallinn, Vienna, Budapest and Paris the past years, all unique and lovely places. This year we decided to travel further south; Barcelona in Spain! From what I've read and heard I think this city has a good mix of things to see and do.

I'm writing my last exam for the semester in just a few days and leave the country shortly after, but I'll squeeze in some time to research about Barcelona. Got any tips for us?