You are asking, how do you buy? Well you see, go to a shop in this forum, and after that click ''Buy'' in the item you are buying. After clicking, it will redirect you to making a new post.
What do you do?
Here is what your psot must be

Subject: Buying [Name Of Object]

Habbo Name: [Insert YOur Habbo Name Here]

Character which you are buying for: [Insert the Name of the Character you are Planning to buy this item for]

Ofcourse, if in your inventory you do not have enough coins, the post will be deleted. If accepted and have enough money a moderator or administrator, will reply with: Buy Succesful.