How do I make my player look and make my bullet move at direction of my mouse

So , how do I get the position of mouse and how do I make my bullet move at direction of the set position of mouse , and how do I make my player look at the direction of mouse ?

You can get a ray from the mouse position looking in the direction by using Camera.ScreenPointToRay

then you use Phyics.Raycast to cast the ray.
so you can have something like

Ray ray = Camera.main.ScreenPointToRay( Input.mousePosition );
RaycastHit hit;
Physics.Raycast( ray, out hit );
if( hit.collider != null ) {
	transform.LookAt( hit.point );
}