What do i have to do to become a nude model?

You can try going to your local university art departments. I have done this type of modeling years ago. I don't think it helped much to increase my confidence, but if you must take off your clothes this is at least a dignified way to go about it. You must be mature and of legal age and you must conduct yourself in a very professional manner in order for the instructors to consider hiring you and an appreciation for the arts will help as well. I appreciate that you demonstrate a modesty about this and that is very commendable.