By default, no widgets will be installed in your VDK Studio software. The list of your available widgets in your workspace side bar will therefore be empty. Once you have created a project, needed widgets will be automatically downloaded.
You can also manually download more widgets from the Resources widget tab.
To be able to use your widgets in the VDK Studio, you will have to first install them or create a new project that needs them (automatic download). They will then appear in your widgets list in the side bar of your workspace.