Low oil pressure message

Oil pressure has little to do with oil level as long as it's full. It is the measure of the oil pressure inside the engine where it passes through all of the bearings and valve train components and related to the amount of force required to make that journey. In this case the first thing to do would be to use an oil pressure gauge installed in place of the pressure switch on the side of the engine and see what the pressure really is. In the case of that warning this is a critical item as the switch only takes about 10 pounds of oil pressure to turn on and off and that engine should have closer to 25 pounds of pressure at idle. The pressure sensor is above and to the rear of the oil filter just above the starter. Usually you can get to it from underneath the car. You will need a manual oil pressure test set, you can usually get them as loaner tools at some parts stores. Then you remove the sensor, replace it with the test adapter and the hose to the gauge. Next start the engine and watch the pressure gauge. At about 1,900 RPMs you should see 45-50 PSI of oil pressure that raises as the RPMs go up, then drops to about 20-25 PSI at idle.

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

The universal style of tester such as these is not as accurate as the specific OE tool that replaces the oil filter and tests there, it can tell if the issue is the oil pump or internal to the engine, so if the external test is somewhat odd you might want to have a dealer test it just to make sure.

Now to correct it the first thing to try would be an oil change, especially if this started after the last oil change. It may not be the correct oil or a defective filter. So I would check the pressure, then if it's low I would change the oil, reset the monitor and check the pressure again, at both a cold start and once the engine is fully warmed up. If the oil pressures are within specification, change out the pressure sensor with a new one and see if the warning stop. If the pressures are low then the likely issue is internal engine wear, especially if they are much higher on the cold start than once the engine is warm. Repairing the engine internally would take care of that, or as a temporary fix you could try a thicker oil, OE oil for that engine is 5W-30 oil, you could go to a 10W-30 or 10w-40 and see what the pressures do then. If they rise and the engine seems happy, you could do that, but it's not the proper repair, however it might be an option.

That would normally be caused by low oil, or if the oil pump pick-up tube was moving and getting out of the oil in the pan. On that engine that isn't likely but it is possible.
To repair that you would need to remove the oil pan and check and repair it or simply replace the pump and tube. On that car it isn't real difficult but it is much easier on a lift.
You disconnect the battery, then install an upper engine support bar. Now you go under the vehicle and remove the A/C compressor and move it out of the way, then the engine to transmission brace image 2 and then the starter. On the front drive version you remove the intermediate shaft and then drain the oil and filter. Then remove the bolts that secure the oil pan. With the pan off you can unbolt the pump, be sure to catch the pump drive shaft. Now you will want to pack the new pump with something like a light grease, Vaseline works good. That way the pump won't be started with dry gears and plates. Now you put the new pump in place and rotate the drive shaft until it seats in the drive inside the engine and in the pump socket. Torque the bolt to 30 ft lb. Now you can clean up the seal surface of the pan and reverse the process you used to remove it. Clean the block sealing surface and apply the new sealant and then reinstall the pan. For the bolts you install the flange bolts first, they get torqued to 18 ft lbs. Then you install the side bolts and torque those to 37 ft lb. Install a new oil filter. Now before you put everything back it is a good idea to just install the starter. And crank the engine over to be sure you get oil pressure. Once you are sure you can remove the starter and reinstall the brace, starter and AC compressor as well as the intermediate shaft.

Before you do all that I might double check that you have the correct amount of oil in it by volume and not using the stick. That engine should take a bit over 4.5 quarts with a filter change.

Sounds like a plan. What you could do as you are going to drop the oil out would be to get a small borescope/endoscope like they have on Amazon and use it to look in there and see if the oil pump pick-up is okay. That would at least tell you if it's in place and not plugged. Then you could plan from that.