Is there a way to just have a max of 1 time jump?,Is there a way so i can just jump one time?

Questions & Answers
1

void Update()
{
if (Input.GetButtonDown (“Jump”))
{
GetComponent().velocity = Vector2.up * jumpVelocity;
}
}
}

2

You need to check if the player is grounded.

Then you can add that condition for jumping (bool value):

         if (Input.GetButtonDown ("Jump") && isGrounded)
         {
             GetComponent<Rigidbody2D>().velocity = Vector2.up * jumpVelocity;
         }