need help with instantiating a gameobject

I am working on a small pong clone and planned on completing it in about an hour and so far i've got it just cant get the ball to respawn. I was able to do this exact process with a different program I was working on last night but cant seem to get it to work here. I have the ball hitting a boundary and destroying the gameobject.

with a OnTriggerEnter2D I have the boundary destroying the ball and trying to instantiate it calling for the ball prefab however it wont instantiate the ball.

when I try to have it be created in the middle of the screen I keep getting errors saying cant convert vector3 to transform when I put a vector3 or a transform in the second part of the instantiate arguements.

Please if anyone knows I would appreciate any help

 

This happens when you try to assign the position to a transform when you really need to sign it to transform.position.