Appeal deadline questions after an unemployment denial (Austin)

My claim was denied after 3 weeks of waiting, and the letter says I have a short window to appeal. It has been a long 3 weeks. The letter lists a deadline and a hearing process, but it is hard to follow. 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.