In case you haven’t figured it out yet, the error in your code is a typo in your start function. Due to this, your code wasn’t able to find an instance of the Ball gameobject which caused the position of your paddle to not update according to the position of the ball, hence making it stationary.
You wrote:
As C# is case sensitive and ‘void Start()’ is a pre-defined method which runs once at the beginning every time you play, therefore the ‘s’ in start must be in upper case like ‘S’, so your code would be:
This will make your paddle move and get rid of the ‘NullReferenceException: Object reference not set to an instance of an object’ error in case you were getting it on your console.
Hope this helps.