How to make gun rotate/point towards mouse cursor 2d style in 3d.

Hello,

I’m a very new unity developer and I am currently making a 2d style game in unity 3d, I’m trying to add a simple gun that points towards the mouse but not in the z-axis. I also want it to rotate around the player meaning I want my gun to stay attached to my player while the other side points toward the cursor.

I also don’t want my gun to be interrupting my player’s movement.
I have very little knowledge or experience with scripting and any help would be appreciated.

Thanks.

UnityUI.