Appeal deadline questions after an unemployment denial - first time posting

I was told my separation was for misconduct, which is not what happened. It has been a long 20 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?

Thanks for writing this out. I went through something close to it 2 months ago, and it settled down once I kept a simple log of every call and form.