Depends on what you're interested in... for example if you're in finance you could do a HBX (Harvard Business School) online course that offers certificates (and college credit, if you pay) in accounting, economics for business, scaling, entrepreneurship, etc., and look into shadowing various banks/hedge funds near Chicago (which I presume is "the city" in Illinois you are referring to) for a week or asking even for a summer internship. If you're interested in social justice/advocacy, lots of non-profit groups/food banks/NGOs in the area as well.

In short, find out first what you're interested in to narrow down what areas to look at. Second take full advantage of your geographical proximity to a city. It's easy to take for granted!