Car shuts off driving down the road
some times the security light comes on
anyone know what what might be going on or how to test?

When it shuts off does it just die like a switch was flipped, or does it stutter to a stop?

Like switch off

Check over the battery cables. A loose connection could cause that.

Did that also some times the security light goes on and off
and some times when turn the key to start it nothing happens then try again and it will start

Define "nothing happens". Do you mean you get no bells, lights on dashboard?

Every thing works but the starter

Get some alcohol and clean the chip(both sides) on your ignition key and try again.

On the 95'*, if the security light is flashing, your starter is disabled. 96 and above, the starter will engage, but the fuel injectors/or fuel pump won't turn on.

Sounds like a VATs issue. Here is how to bypass it. https://www.gmforum.com/electrical-133/bypass-vats-92-99-a-279119/ You can also try a different key.

Thanks