One-day trekking on Hua Shan

Hi, I am planning a one-day trekking trip on the mount and I have a few enquiries that I hope you can help me with.

1) I looked at the other Q&As there is a bus leaving Xi'an at 07:00. Which bus is that and where can I find more information about it?
2) Are there any local delicacies worth trying at the mountain top? and where can I find more information about it?

I will be very grateful if you can assist me in my enquiries. Thank you so much.