Single vs. Double Room

Im studying abroad in barcelona this coming semester and I am going by myself. I would love a single room as I dont really like to sleep in same room as someone else, but I am worried that making friends to go out and travel with may be significantly harder if I dont have a roommate in same room to make it easier. I am also thinking maybe people requesting single rooms may be less outgoing in general(making my other roommates less likely to become good friends of mine). Wondering peoples thoughts on this and if anybody experienced anything abroad like this