Can I use an older iPad to charge an iPhone by connecting these dongles together? By this, I mean you have the iPad, you then plug in the lightning to usb adapter (where you insert usb sticks and the like), connect the usb to lighting charger to the adapter (which you charge devices with) and connect the iPhone to the cable, similar to how the newer USB C iPads work.
No, those devices don't work that way.  You can only do that with the newer USB-C devices.