CS 1 is a required class for all CS freshmen, and pretty chill. Each week a different professor comes and talks about their research for an hour. You have to take notes and pay attention though, because you're quizzed on the lecture content during discussion on Fridays. The lectures themselves are mixed. Some professors (like Len Kleinrock) give amazing presentations. Others drone on for too long. There's also an essay you have to write during finals weeks about what you learned from all the lectures. The course is designed so everyone gets As, so don't sweat it.