Denied unemployment, how do I appeal? (update)

My claim was denied after 20 weeks of waiting, and the letter says I have a short window to appeal. There are 15 people counting on me, so I am trying to be careful. I have not done a hearing before and I am nervous. If you have appealed before, what helped you prepare?

Legal aid offices and some workforce centres help with unemployment hearings at no cost. A call is worth it.