Denied unemployment, how do I appeal? - any advice?

My claim was denied after 16 weeks of waiting, and the letter says I have a short window to appeal. Thank you in advance. I have not done a hearing before and I am nervous. If you have appealed before, what helped you prepare?

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.