I have made a costume to a player and it works fine on 3rd person mode, but in first person mode the costumes head is on the way of the camera. How is it possible to make the costume's head invisible only to the player wearing it?
I don't know about that, but a quick temporary fix could be to adjust the camera position forward until the costume no longer blocks the view. That's what I did to make the scroll wheel roll between 3rd and 1st. If you set the minimum camera distance to a negative value, the camera will be in front of the player's face, not in the head.