Have Camera Render First Person Arms But Not Body.

ok I have a kit for this on sellfy but i wont post it here

its rather simple. Step1.
Split the modles matierials into 3 parts. the head. the arms and the full body this can easily be done in blender but there is an asset called fpsmesh that does it in unity

Step2. get an invisble shadow caster shader and apply it to your body at start so that when you spawn in it disables it for you

step3. Profit

@Noah First reset transforms of your player gameobject to zero, then move your main camera inside player gameobject as child and reset its transforms to zero. Adjust camera position and rotation accordingly how you want it in game, keeping game window side by side with scene window will help you in this. Now whenever you translate your player, camera will move with player.