Finding position of a game object


I'm a complete beginner at Unity, and I've just started attempts at coding (I'm using it for my degree project, perhaps unwisely as I feel completely in over my head). My game aims to take the position of an object (which is controlled by a fiduciary marker) and being able to manipulate other game objects positions with it. However, I can't figure out even the basics so far, as I'm struggling to find the necessary javascript code to find the x and y co-ordinates of the object (it moves on a 2D plane, so Z isn't an issue). What is the code I need?

I have an idea how the code should look, but I'm just struggling to figure out how you'd write it in Unity. Heres a rough example of what I want it to do (obviously not in code yet).

Find the Xposition and Yposition of this gameObject (the one controlled by the fiducial, which I hope to apply this script to) For Zpos = 0 to 150, (this allows for depth) If a gameObject exists at (Xpos, Ypos, Zpos) Then that gameobject should gain an effect to show it has been found (glowing perhaps) If object is found, stop loop.

Sorry for being a completely beginner, I understand people normally come for help with a bit more than this.

This will print the GameObject that it is attached to position in the Console. You could use that information for any other purpose

//Unity will constantly check the position of the GameObject.
function Update () {
    //Creates a variable to check the objects position.
    myPosition = transform.position;
    //Prints the position to the Console.

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