How can you add new atributes on list a property page, I need more details from the owner of the property, for example his phone number or his email address.
If you mean listing attributes then please try to add new attribute in Listings/Attributes.
If you want that listing owners (vendors) fill in this attribute then please check Allow front-end editing option for this attribute
If you want to make this attribute required then please check Make this field required option for this attribute
If you want to show this attribute in a single listing page or in a listing block then please choose an area in Areas option in an attribute