Low oil pressure

We need to start with checking the oil level and make sure that is okay.

Then here is a guide that covers the basics on low oil pressure:

https://www.2carpros.com/articles/high-or-low-engine-oil-pressure

Clearly we need to suspect it was related to what repair you made but we need to start at the basics first or we could waste time and money on trying to figure out how this would be related. The vehicle is telling us what the issue is so we need to find out if this is a mechanical issue or a sensor issue.

I attached below the process on how to test the oil pressure. Let's start with this and go from there.

My car won’t start?

Correct. If it is telling you that the oil pressure is low then it is preventing the start to protect the engine. So we need can still get pressure when just cranking the engine. However, if you want we need to start with checking the oil and if it is low, top it off and then see if the engine will start. If not, we need to find out if this is a sensor issue or the actual pressure is low.

Okay, I don’t have a tester, I do have oil at level. I did order crank and cam sensor , and was going to check screen as well in oil pan/pump.

Okay. Are you saying you are going to drop the pan and look at the oil pickup tube/screen? If that is the case, then you need to look for metal in the pan as well. Just to be sure it is not a larger engine issue.