An empty screens probably means that you haven’t yet created an individual sitemap. Have you?
A sitemap has to be created in /etc/openhab2/sitemaps. Either using a ssh connection or with the Eclipse Smart Home Designer software. You have to name it according to your definition inside the sitemap. You can have a look at the Wemo binding documentation:
The sitemap there is called “demo” (sitemap demo label=“Main Menu”). So the filename has to be demo.sitemap. This file has to be put into the above mentioned folder.
And you have to create an item file, where you put your item definition in. Again, an example especially for the wemo configuration can be found in the above link. You can create an item file for this (as for the sitemap) and put it in etc/openhab2/items. Or you can use PaperUI to link the channels of the things to the item names.
And again: Take a close look at the documentation at docs.openhab.org. You can find tutorials for Beginner and Demo installations there. Also you can find a user manual there where all these thing/channel/item/sitemap stuff is explained. And it’s explained much better then I could ever do it…