Many tools provide the ability to create objects.
The type of object created and the specific creation steps depend on the tool. For steps on creation, see the documentation for the specific tool.
In most cases, you can right-click either an existing object or an empty location in the scene to create an object. Often, you can keep holding down the right-click button to simultaneously create and drag the object (refer to Dragging (Moving) Objects).
Depending on the specific tool, you might need to first select an appropriate asset in the Library Browser. Some tools require an asset to be selected, while others will change their behavior depending on whether an asset is selected.
Some types of objects can be created by dragging an asset from the Library Browser into the scene by clicking and dragging the object. For example, dragging a Prop Asset into the scene adds a prop point to the scene and automatically switches the currently selected tool to the Prop Point Tool.