I have a 1994 Ford Taurus SE 4 door and for some reason usually gets 28 miles to go a gallon but now the gas is getting eaten up really quick and I don't know why
Your Taurus will have a fuel pressure regulator and a fuel pressure sensor. If either of them is failing, your fuel mileage gets terrible because the fuel pressure is too high. Have your fuel pressure tested. Mine did that and it showed a code for fuel pressure sensor. Replaced it, easy to reach, only $40 for Bosch original part. Don't replace it unless you get that code and I don't recall the number.
When was the last time you changed the engine air filter?
That's correct. Check the air filter first. That would be the fastest and easiest thing to fix and they're only ten bucks.