Can we just hang gourds and not put copper coins?

You can't. It is the gourd that means longevity and wealth, and "Fu Lushou" is all gone. So people especially like all kinds of ornaments and ornaments made of gourd. And "money hanging gourd, prospective owner Fu Lushou" refers to the ornaments made of copper coins and gourd, which means that if the ornaments made of copper coins and gourd are hung at home, the owner of this home will have a complete Fu Lushou in the future.