No Park lights (help)

There are ground wire in the harness, must be properly grounded
All ground wires seem to be connected on the front harness.
Here's what I would do for what it's worth.......

Connect everything and pull the switch to the first contact. Connect your test light to the negative post of the battery and confirm that it works. Head straight to the light that is not on and remove the bulb. Probe the positive contact with your test light. If it lights up, you have a grounding issue. If it doesn't light up, work your way back up the wiring harness until you find power. That will help isolate where your issue may be.
That was one of my first test no power to the bulb. I do have brake lights but no rear fender markers side markers or Park lights, I seem to have power out of the bulkhead and out of the switch to too, I know I'm missing something