Appeal deadline questions after an unemployment denial (Chicago)

I was told my separation was for misconduct, which is not what happened. I worked as a call-centre agent before this. The letter lists a deadline and a hearing process, but it is hard to follow. Did you bring documents or only talk?

Thanks for writing this out. I went through something close to it 5 months ago, and it got easier once I kept a simple log of every call and form.