help with first person viewpoint

Godot Version 4.2.2
I am making a first person game where i want my camera to be able to look down and see the body similar to this
but i have no idea where to start if have my animations and my player model but i dont know how to get the arm to follow the camera and also how to no have the model clip through the camera when an animation plays i have a good shader to make the player a different fov and not to clip through walls i am also making my game multiplayer so i cant delete the head or at least i need to find a way to show the head to other players

Just you need to use layers/masks, you can watch this video and if you not know where to start, you can find many fps controller tutorial series in YouTube