RPG Text 2D on Object Interaction Javascript

This has been driving me insane! I've been watching videos on youtube, and some of the unity tutorials, but I cant find out how to code this.

This is the code I have so far.

// var dialogue = "Hello World";

// function OnCollisionEnter2D (coll: Collision2D){

// if((coll.gameObject.tag == "Player") && (Input.GetKey(KeyCode.Space))) {

// }

// function Update(){

// if (Input.GetKeyDown(KeyCode.Space)); {}

// function OnGUI() // { GUI.Button(Rect(150,375,300,30), dialogue);

}

How can I fix this code to make it interact with something? I want to be able to have my player walk up to an object and examine it and receive text back..