To learn how to be an authentic person, you must first love yourself unconditionally, without wavering and accept who you are flaws and all. You must be completely honest with yourself and remain true to your inner self.
An authentic person will reflect a sound moral character and values outward towards others. Their open-minded, deep thinkers who are not afraid of being vulnerable.
To be an authentic person, you must face your inner doubts and fears, accept your inabilities and overcome the mental limitations you set in your mind. And admit the inadequacies and weaknesses within yourself.