Got a denial letter for unemployment, what now? after 6 years as a security officer

My claim was denied after 12 weeks of waiting, and the letter says I have a short window to appeal. This is my first time dealing with any of this. I have not done a hearing before and I am nervous. Did you bring documents or only talk?

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