Adding connectors with lines

[mmabc]

I've seen shapes like a cloud that have handles that allow you to drag lines and connect to other shapes.  I want to be able to add those to other shapes that don't have that.  I know virtually nothing about editing shapes.  I'm wondering if anyone can show me how to do that and or link me to basic intro articles on editing shapes.

I've looked one shape, an Ethernet.  I can see all the control handles, but I don't see how the link to lines connectors.

[Paul Herber]

Those control handles link to Geometry sections. It's the Geometry sections that contain the wiring for the connector, the control handle determines its end.
Look in the shape's shapesheet.