I love to argue about this one because I always turn out to be right! ‘Personne !’ means nobody but ‘une personne’ is a person. This is ‘une personne’ whether the person in question is a man or a woman.
Example: (in a barber’s: “Cette personne voudrait qu’on coupe sa barbe – this person would like his beard shaved/trimmed’. Seeing the doubt, not to say, suspicion, on my interlocutor’s face makes me hope that they will go to the dictionary, and discover that I am telling the truth.
Yes, une personne can be a man.