Got a denial letter for unemployment, what now? - 13 months and counting

I got a denial letter last week saying I left my job voluntarily, but I was let go as an event coordinator. It has been a long 13 weeks. I have not done a hearing before and I am nervous. If you have appealed before, what helped you prepare?

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