Add Objects to your floorplan from left-panel. Edit Objects in the right-panel.
Open the Objects section in the top drawer of the left-panel to search through the library of objects. Search for the name of a specific Object, choose from your saved Favorites, or browse through the categories. Once you find the desired object, simply drag & drop it onto the diagram!
Once an object has been added to the diagram, it can be edited from the Edit Object section of the right-panel.
There are additional options for arranging objects available in both the Arrange menu, the toolbar above the diagram, and as keyboard shortcuts.