What can an American expect from a British education system?

Hi, I'm coming from an American high school and am probably going to King's College London. I don't want to go in totally unprepared. How is schooling different in terms of expectations/requirements/ignments/te… and student relations, that sort of thing? (I'm going for an English degree, by the way). I know generally the Brit system is more demanding. I was a good student, but should I expect hardship?