There are always events going on around campus. Luckily, they are all listed on calendars to make it easy to see what is happening. http://illinois.edu/calendar/list/7 has links to many of these calendars. Some worth noting include the academic calendar (http://illinois.edu/calendar/list/557), the CS department calendar (http://illinois.edu/calendar/list/2654), and ACM’s calendar (https://acm.illinois.edu/). Lastly, Facebook groups like ACM and Computer Science generally have a lot of events thrown onto them. I would highly recommend that you subscribe to these calendars to stay up-to-date on what is going on around you.