Appeal deadline questions after an unemployment denial

I got a denial letter last week saying I left my job voluntarily, but I was let go as a project coordinator. Any experience at all would help. The letter lists a deadline and a hearing process, but it is hard to follow. If you have appealed before, what helped you prepare?

Stay calm and stick to facts. Mine lasted about thirty minutes and felt more like a conversation than a trial.

I printed my emails in order and wrote a one-page timeline. The hearing officer kept going back to it.