Did you check the fuse?
Here's what I'd do........
Find the Netural Safety Switch, it should be located at the bottom end of the steering column, should have a Blu/green, green and two purple wires coming out of it. The green ones are for your backup lamp and the purple ones are the NSS. Put a jumper between the two purple wires and see if it turns over if it does it's the NSS. If it doesn't turn over check to see if you have 12 volts on the purple wire leading to the ing switch, if you don't have 12 volts, it might the ing switch or the wire powering the ing switch (check the fuse)
Make sure the car is in park and the emer brake is on, take a screwdriver and be very careful, touch it to the large stud on the starter (The one that the battery cable is hooked to) and the "S" terminal on the starter (should be a purple wire hooked to it).
If the engine turns over, it's not the starter. Then use a multimeter and check for continuity between the "S" terminal end of the wire and Netural safety switch. if no continuity......... check the firewall bulkhead connector for corrosion etc...... if that doesn't fix it, run a new, temp jumper wire from the "S" terminal on the starter to the eng (not the switch side) side of the NSS. If it works with the temp wire you need to replace the purple wire from the "S" terminal on the starter to the NSS.