Need help with picking up items by typing "E"

So I'm still working on my game and I've come across another problem I can't solve on my own, and can't seem to find a tutorial on YouTube or anywhere else that can help me with it.

I'm wanting to make a script that will allow the player to pickup something when they are looking at it by pressing "E" on the keyboard Similar to the way you can pickup stuff in The Elder Scrolls Games. I need a script that will be able to pickup ammo and add it to my Current Ammo, when a player looks at a "clip" and presses "E" I would also (if Possible) like to make it so you can drag the item around by Holding down "E" (Again similar to games like Skyrim) Can anybody help with this?

Here is my Script that takes care of the guns and ammo. (if needed)

 var PlayerTransform : Transform;
 var PlayerScript : Player;
 var RotationSpeed : float;
 var PlayerCamera : GameObject;
 var IsAiming : boolean = false;
 var GunAnimationHolder : GameObject;
 
 //Targets
 @HideInInspector
 public var TargetXrotation : float;
 
 @HideInInspector
 public var TargetYrotation : float;
 
 @HideInInspector
 public var TargetXrotationV : float;
 
 @HideInInspector
 public var TargetYrotationV : float;
 
 // Gun Specs
 var MaxClipSize : float = 10;
 public static var AmmoInCurrentClip : float = 10;
 public static var ExtraAmmo : float = 0;
 var MaxCarringAmmo : float = 30;
 
 //  Bullets and shiz
 var Bullet : GameObject;
 var BulletSpawn : GameObject;
 var BulletSound : GameObject;
 var FireRate : float;
 var FireTimer : float;
 
 //Recoil
 var Recoil : float = 3;
 var RecoilAimingIn : float = 3;
 var RecoilAimingOut : float = 6;
 
 //Reloads
 var ReloadAnimation : GameObject;
 var ReloadSound : GameObject;
 var Reloading : boolean = false;
 var ReloadName : String;
 
 
 
 
 function Update()
 {
     AimingInController();
 }
 
 function AimingInController()
 {
     IsAiming = GunAnimationHolder.GetComponent(Player).AimingIn;
 }
 
 function LateUpdate () 
 {
 
 if (AmmoInCurrentClip > MaxClipSize)
 
 AmmoInCurrentClip = MaxClipSize;
 
 if (ExtraAmmo > MaxCarringAmmo)
 
 ExtraAmmo = MaxCarringAmmo;
 
 if (FireTimer < -5)
 FireTimer = -5;
 
 if (MaxClipSize < 0)
 
 MaxClipSize = 0;
 
 if (AmmoInCurrentClip < 0)
 
 AmmoInCurrentClip = 0;
 
 if (!Reloading && AmmoInCurrentClip < MaxClipSize && ExtraAmmo > 0 && Input.GetButtonDown("Reload")&& IsAiming == false)
     {
         Reloading = true;
         ReloadSound.Play();
         ReloadAnimation.animation.Play("Reload");
     }
     
 if (!Reloading && AmmoInCurrentClip == 0 && ExtraAmmo > 0 && Input.GetButtonDown("Fire1") && IsAiming == false)
     {
         Reloading = true;
         ReloadSound.Play();
         ReloadAnimation.animation.Play("Reload");
     }
     
 if (Reloading && !ReloadAnimation.animation.IsPlaying(ReloadName))
 {
     if (ExtraAmmo >= MaxClipSize - AmmoInCurrentClip)
     {
     ExtraAmmo -= MaxClipSize - AmmoInCurrentClip;
     AmmoInCurrentClip = MaxClipSize;
     }
     
     if (ExtraAmmo < MaxClipSize - AmmoInCurrentClip)
     {
         AmmoInCurrentClip += ExtraAmmo;
         ExtraAmmo = 0;
     }
 Reloading = false;
 }
 
 var MyBulletSound : GameObject;
 
 if (Input.GetButton("Fire1") && AmmoInCurrentClip > 0 && !Reloading)
 {
 
     if (FireTimer <= 0)
     {
 AmmoInCurrentClip -= 1;
 
 TargetXrotation += (Random.value - 0.5) *Mathf.Lerp (Recoil, RecoilAimingOut,0);
 TargetYrotation += (Random.value - 0.5) *Mathf.Lerp (Recoil, RecoilAimingOut,0);
 
 
         if (Bullet)
         {
         Instantiate(Bullet,BulletSpawn.transform.position,BulletSpawn.transform.rotation);
         }
         
         if (BulletSound)
         {
         MyBulletSound = Instantiate(BulletSound,BulletSpawn.transform.position,BulletSpawn.transform.rotation);
         }
         
     FireTimer = 1;
     }
 
 
 }
 
 if (Input.GetButton("Fire2") && !Reloading )
 {
     Recoil = RecoilAimingIn;
 
 }
 
 if (Input.GetButton("Fire2") == false || Reloading )
     {
         Recoil = RecoilAimingOut;
     }
 
 
 FireTimer -= Time.deltaTime * FireRate;
 
 transform.position = PlayerCamera.transform.position + (Quaternion.Euler(0,TargetYrotation,0)* Quaternion.Euler(TargetXrotation,TargetYrotation,0) * Vector3(0,0,0));
 
 TargetXrotation = Mathf.SmoothDamp(TargetXrotation, -PlayerCamera.GetComponent(MouseLook).rotationY,TargetXrotationV,RotationSpeed);
 TargetYrotation = Mathf.SmoothDamp(TargetYrotation, PlayerCamera.GetComponent(MouseLook).RotationX,TargetYrotationV,RotationSpeed);
 
 transform.rotation = Quaternion.Euler(TargetXrotation,TargetYrotation,0);
 
 
 }