Input.GetTouch(0).phase == TouchPhase.Began is the equivalent of Input.GetMouseButtonDown (0)
Input.GetTouch(0).phase == TouchPhase.Ended is the equivalent of Input.GetMouseButtonUp (0)
What is the equivalent of Input.GetMouseButton (0)?
Input.GetTouch(0).phase == TouchPhase.Began is the equivalent of Input.GetMouseButtonDown (0)
Input.GetTouch(0).phase == TouchPhase.Ended is the equivalent of Input.GetMouseButtonUp (0)
What is the equivalent of Input.GetMouseButton (0)?
Input.touchCount > 0
but still depends what you really want. Maybe is better for you:
Input.touchCount == 1