Denied unemployment, how do I appeal? (Tucson)

I got a denial letter last week saying I left my job voluntarily, but I was let go as a graphic designer. I am in Tucson, in case local advice matters. I have not done a hearing before and I am nervous. Did you bring documents or only talk?

File the appeal before the deadline, even if you are unsure. You can gather documents afterwards. That is the one part I would not wait on.