Pong (Need Help)

This is my first project in Unity and it has been really good to get a good start on coding etc!
I’ve made the actual game and everything works but i can’t seem to adjust my settings so that everything works just perfectly. Would anyone with a good knowledge in unity/coding help a guy out here!
After the ball goes out of play it restarts instantly and the ball goes flying off, making it hard to judge and sometimes giving the player many points. How can i make a restart button or something like that?

You can use : Destroy(Ball) and you can instance another new in the place you want.