Elevator Script ?

I guess by pressing E, you mean pressing E while looking at the elevator?

First, you should check if E is being pressed. If it is, make a raycast to interact with the elevator object. Upon interaction, translate the elevator toward one of the two transforms that indicate the two different floors.

The best(and easiest) way would be to animate the elevator, either using Unity's animation panel or animate it using your favorite 3d app. Now assuming you have animated the elevator, lets get scripting.

 var isAtOriginalPosition = true; //Variable to control if the elevator is "up" or "down" 
 
     function Update(){
         if(Input.GetKeyDown("e")){
             ActiveElevator();
         }
     }
     
     function ActiveElevator(){
         if(isAtOriginalPosition){
             animation["animationName"].time = 0;
             animation["animationName"].speed = 1;
             animation.Play("animationName");
             isAtOriginalPosition = false;
         }
         else{
             animation["animationName"].time = animation["animationName"].length;
             animation["animationName"].speed = -1;
             animation.Play("animationName");
             isAtOriginalPosition = true;
         }
     }

This is a script controlling where the position of the elevator is. It is very basic and works. HOWEVER this script is lacking something, you will properly notice the limitations of the code I enclosed(the code is not intended to cover every aspect or problem, etc. but merely a demonstration.).

I will strongly recommend animating the object, and use scripts to activate it. However if you want to use code only you could use something like Mathf.Lerp to 'Lerp' the position to where you want it.

EDIT: If you want to make better use of code without using animations listen to Statement.

it's very usefull

A ready example might help [elivator example][1]https://crackpracgameshowcase.blogspot.com/p/creating-a.html