Check out example codes for "Unity make homing missile 2d". It will help you in understanding the concepts better.
Code Example 1
Vector2 direction = (Vector2)Target.position - rb.position;
direction.Normalize();
float RotateAmount = Vector3.Cross(direction, transform.up).z;
rb.angularVelocity = -RotateSpeed * RotateAmount;
rb.velocity = transform.up * Speed;
Learn ReactJs, React Native from akashmittal.com