My calendar won't move to i cloud, now I cant close it! New to apple, please help.

New to apple. Just bought the new macbook pro with retina, someone tried to sync, or move, my calender to Icloud, a message popped up saying: "Couldn't move your calendars to icloud because an error occured. please make sure you're connected to the internet." When I click try again later, nothing happens, when I click try now, the message simply reappears. I cannot get rid of it! Cannot close calendar either. Wont even let me restart. What the heck is going on. Im hoping its something incredibly easy that I am simply overlooking! Any help would be greatly appreciated. Thx!