Drivers side brake/parking light not working?

This sounds like the TIPM is going out which is common in these cars, but we should check the system ground as well. Here are the headlight and taillight wiring diagrams so you can see how the system works and I have included a guide to help you test the ground which I have marked in the diagram.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

If the ground is good, I would replace the TIPM, here is how. It is easy because it-self learns when installed. Check out the images (below). Please let us know how it goes.

I will look into this. I greatly appreciate the help. I'll let you know how it goes.

Okay, so with the headlights on and left blinker on (where currently the left blinker doesn't work), using the tester, I touched the blinker/brake light ground wire, and the light comes on. That suggests to me, if I'm reading right, the ground is the issue.
So, I just need to find the ground connection. I found two red prongs on each side of the front end of the center console, but no wires connected to them. I need to figure out exactly what I'm looking for.

OK, so with the headlights on and left blinker on (where currently the left blinker doesn't work), using the tester, I touched the blinker/brake light ground wire and the light comes on. That suggests to me, if I'm reading right, the ground is the issue.
So I just need to find the ground connection. I found two red prongs on each side of the front end of the center console, but no wires connected to them. I need to figure out exactly what I'm looking for.

You can just add a ground to the circuit if that would be easier. (black wire) Good find. The ground says it is between the body floor and between the seats.