'95 Riviera Shutting Off

I have a 95 Riviera 3.8 SC, and it shuts off going down the road. The two owners before me forgot to tell me they put premium in it, well i put regular...would that shut my car down or could it be something else....thanks in advance

Poor fuel (low octane), would not cause it it shut off, however it would cause poor performance. When the knock sensor detects knock, the PCM will retard the timing as much as 10 deg to compensate.
You need to see if it has codes first, and post back.

I'm new to all of this, how exactly do i check to see if it has codes.....i know probly a stupid question....

You will need a scanner. Take it to AutoZone or Advanced and ask them to do it.

Check timming
Add some fuel system cleaner to a full tank of gas
Change spark plugs, air filter, PCV valve, and fuel filter. That'l probably fix your problem. You should always give a car a good tune-up when you buy it.