Got a denial letter for unemployment, what now? (update)

My claim was denied after 7 weeks of waiting, and the letter says I have a short window to appeal. I worked as an IT help-desk technician before this. 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.

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