What is wrong with my 2005 Ford Taurus?

I was driving my 05 taurus and pulled over to adjust setting on my portable gps, but when I tried to drive back onto the freeway, my car wouldnt move. I could put it into drive (and reverse) but the car wouldnt move. Why? There were no check engine lights on (or any other lights). The only fluid under the car was from my a/c. I had the dang thing towed back to my house,but am just not sure where to begin to look under the hood and really dont want to pay a fortune for a n=mechanic to look at everything before saying what it is.

first thing is to check the tranny fluid for color and smell.

color should be light red
and if it smells burnt then problem.

It's light read and smells like transmission fluid.

I also checked the cable to see if the sensor was moving when I shift gears and it is.

Id hate to say it but you might have to bring it to a tranny shop or dealer.

this is ford taurus common failure like i said i had three they all went the same way. one only had 33 miles on it. ford forgot to drill a three dollar oil hole for one of the sprage clutchs.trannys are built years in advance would cost to much to tear down and fix.to fix was make a fast left turn and the oil would splash on the clutch.thats what they told me to do. i left the car right there and walked away.never made a payment to this day i never showed up anywere on credit ratings.only had it a day.

be were the new taurus is a rebadged ford five hundreds.the five hundreds did not sale so they have plenty of them.i road tested the car when i first came out, it comes no where near a taurus.it is a cheap peice of junk.its also badged as a sable.