It's pretty late right now, so I don't have time to look at this in depth, but I can at least fix your broken code and explain why it's wrong. I remember what it's like starting out :).
So, first I'll explain what's wrong.
Your broken code:
function OnTriggerStay (col : Collider) {
if(col.gameObject.tag=="jumpPad") {
Debug.Log("HOVER");
this.transform.position.y =+5;
this.transform.position.x =+3;
}
}
Basically, your syntax is just wrong. You have =+ instead of +=. That's it.
Paste this into your code and it will work:
function OnTriggerStay (col : Collider) {
if(col.gameObject.tag=="jumpPad") {
Debug.Log("HOVER");
this.transform.position.y += 5;
this.transform.position.x += 3;
}
}
Next, I would change OnTriggerStay to OnTriggerEnter. OnTriggerStay will execute as long as the player is within the trigger. This might work in some cases, but in others, it might cause it to execute multiple times.
OnTriggerEnter will only execute once, when you enter the trigger.
So, now your code isn't broken. However, I don't think this approach will work very well. You're using Unity's standard character controller, which deals with physics and rigidbodies, as others have said. You're directly manipulating the object's position, which the physics and rigidbody are also manipulating behind the scenes, so you're effectively fighting the physics engine.
I would strongly recommend you use Rigidbody.AddForce(), as others have suggested. Look into it and try to figure it out. That's the best way to learn. Don't give up though, I remember when I first started--it's not easy.
Also, if you want a good place to practice javascript (and programming in general): codecademy.com is great for beginners.
And once you get comfortable with that, I would consider switching over to C# for Unity, eventually. Take that with a grain of salt though. It's just my opinion.