In Editor, you will see a list of widgets under the Widgets panel on the left. Those widgets are organized into libraries (e.g. Basic Widgets or iOS Simkit).
You add widgets to your screen by simply dragging them from the left hand panels onto your current screen.
Widgets can include actions, which means that some widgets will include pre-built interactivity. You’ll find those actions in the Actions panel.
When you add a widget to your screen from the Widgets panel, and that widget is subsequently updated in its parent library, those updates will not affect the widgets you previously added to your screens.