1999 Ford Taurus OIL PUMP

You're in for a good time...
Check the link

https://www.2carpros.com/articles/mitchell1eautorepair-car-repair-manuals

or just go to the autozone home page and navigate to your vehicle from the repair guide.

Oil pump is behind front cover, behind harmonic balancer, and behind just about everything else.
Oh, and you need to remove the oil pan, too.

Before you tackle the oil pump, hook up a pressure gauge to read actual pressure. You may just have a defective oil pressure sending unit.
If you have low pressure, try using the next weight motor oil. Eg: If you usually use 10W30, try going with 2qts of 10W40 and 3qts 20W50 mix. The weight mix is not critical. Just don't mix oil manufacturers / brands.