As an undergraduate, my time will be split among lectures and supervisions. At least two times a day, I will be attending lectures on topics relating to the paper I'm reading. Technically, I am able to attend any lectures I wish in the entire university. In reality, I expect to only go to lectures specifically related to my course -- at least during the first term.
I'm reading for two papers during Michelmas term, so I have one supervision some weeks, and two supervisions on others. During supervisions, I get together with that paper's supervisor and 1-3 other students reading for the paper to discuss the week's readings for about an hour. Then I go into a private session with the supervisor to discuss a paper I have sent him around 48 hours prior.