Making a sound using collisions

I'm completely new here. I tried looking up various tutorials but it doesn't help. I have a script somewhat it doesn't do anything as of right now. Please no professional stuff that will make me just do a copy and paste. I get no error it doesn't play a sound. also I don't even know if I'm even making a correct trigger collision area. I copy and pasted a floor block and checked off is trigger, dragged on both the script and the sound on the same block. Here's a video if it helps Thanks for reading! I made the audio file a .ogg

 var HallwayScare : AudioClip;
 
 function OnCollisionEnter (collision : Collision) {
   audio.PlayOneShot(HallwayScare);
   //  audio.Play(HallwayScare);
 }
 
  //@script RequireComponent(AudioSource)