POST without “add new custom field” VS PAGES without “categories”

Hi, I have already installed the Hotelica theme. Following the instructions on the “documentation” I am told that in order … “To add room you should create room category first” which is created on POST. Ok, but then in order to “add a new custom field” for the price and value … (To add rooms click on Posts > Add New and fill all the details), this feature is NOT available on POST. On the other hand this is featured on PAGES but then on PAGES you do no have the “categories” to choose from, created on POST. Am I wrong ? Am I missing something here? What … ? I would appreciate your help. Thank you.

The page I need help with: [log in to see the link]