Denied unemployment, how do I appeal? - 4 months and counting

My claim was denied after 19 weeks of waiting, and the letter says I have a short window to appeal. I do not usually post, so bear with me. I have not done a hearing before and I am nervous. 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.