Must reads for someone just getting into books

I (20m) have never really gotten into reading books for my own pleasure. I’ve always just read what school had obligated me to read. Now that I’m switching majors from law to international business administration, I have a half year in which I’m completely freed from my duties in university. During this period I’m planning to make it a goal for myself to broaden my knowledge about the world and everything that happens within it. This includes philosophy, relationships, economics, social commentary, political ideologies, biographies etc, etc… What are some books that are considered a must read for this kind of thing?