So, from what I can tell from the manual.. the Paul has pretty straightforward preset-saving to PC channels…SO You should be able to control the Paul either with the H9 PC map, or directly from your Switch Dr. I personally would opt for controlling the Paul with the Switch Dr, and the H9 with the switch Dr.
As far as the detail go, you need to fix the part about you not knowing a lot about MIDI for this to work. All three of these pieces of equipment have extensive MIDI capabilities, and MIDI is not hard to learn. Any attempt at us trying to walk you through it would be foolishness, unless someone has your exact setup. BUT, you can learn what you need to in an afternoon.
Now, if you think you are ready:
I would start with setting the H9 to channel 1, and the Paul to channel 2 (or whatever different channels you want). Then I’d work on creating presets on the Paul, and getting the Switch Dr. to cal them. Once you can do that, everything else should fall into place.