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

My claim was denied after 21 weeks of waiting, and the letter says I have a short window to appeal. There are 11 people counting on me, so I am trying to be careful. My employer's version of events does not match mine, and I have emails that show it. 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.

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.