The fallacy in the statement "I met one rude person from New York, so everyone from New York must be rude" is known as "hasty generalization" or "fallacy of insufficient sample size." It is a type of fallacy where a conclusion is drawn based on an insufficient or unrepresentative sample size.
In this case, the person is making a generalization about an entire group of people (everyone from New York) based on the behavior of just one person (the rude person they met). This is an illogical and unfair inference, as it does not take into account the vast diversity and individuality of people from New York or any other group. It is not a valid or logical way to form conclusions or make judgments about a larger population or group based on limited or anecdotal evidence. It is important to recognize that individuals vary greatly within any group, and making sweeping generalizations based on limited experiences is not a fair or accurate representation.