So I bought this 94 z28 v8 convertible Camaro. The dude before me had the alternator, air intake, spark plugs, and headers disconnected. I put everything back together, including installing a touch screen CD player and speakers. I go to turn it on and the security light is on. Won't let me start it up. It sounds like it's trying.. But nothing happens. How do I get through the security lockout?

 

Common issue i think. I suggest just bypassing the Pass-Key functionality by installing a resistor. Good details here if you spend the time to read and understand it:
4th Gen LT1 F-Body Tech-PassKey/VATS