1995 Chevy Lumina

Hi:
remove the battery and take it to a nationally recognized parts store. Have them load test it. Also, you can turn the lights on and have a helper turn the key to start to see if the lights dim to almost nothing. If so, the battery is bad or needs recharged.

If the battery is good, have a helper turn the key to start and check if there is power to the smaller wire going to the starter. If so, the starter is most likely the problem.

Before replacing anything, let me know what you find.

Also, is the security light flashing when you turn the key?
Joe