Learn to troubleshoot.
No1 is watch headlights while twisting the key to start, looking for ANY change. LISTEN with hood and driver's window open, can you hear the "click" of the starter relay? As someone suggested..........wiggle the shifter from park through reverse and neutral while holding the key in "start" and listen for any click/ crank/ etc
If that gives you nothing, concentrate on the starter relay and it's wiring
MINIMUM you need and NO EXCUSES for electrical troubleshooting is some sort of test lamp, a couple or 3 robust "alligator clip" wires, and a multimeter
Now, look at starter relay..........there are 4 terminals. The "big stud" is battery, and also one of the relay contacts. The "big square" screw terminal goes to the starter. So first, see if the starter will crank. Make CERTAIN the transmission is in park/ neutral, and jumper "anything metal" across those two (the two largest, and bare) terminals. Starter should crank engine
If that is OK, now troubleshoot the relay magnet/ coil circuit. Your start wire, usually yellow, comes from the ignition switch.........through the bulkhead connector........and out to one of the two push on "flag" terminals of the relay, which is one coil terminal. Through the coil and out the remaining flag terminal, that wire goes down the firewall to the transmission and connects to the MIDDLE terminal of the neutral safety switch, which grounds that wire in park or neutral.
So first unplug the NSS wire going down the firewall. Take a "clip" wire and ground that flag terminal. Try the key. If it works, the trouble is in the NSS wire, the NSS connector or switch, or the trans/ shifter linkage
If it will not crank, "back probe" the yellow wire from the remaining flag terminal, and test it for voltage when the key is in "start." If you have voltage and the other relay "flag" terminal is grounded, and it will not crank,.................replace the relay