What do you mean by "calling someone by their first name"? Call the person directly by their name.
1. Calling someone by their first name means calling the other person directly by his or her name. The Chinese title is a very complex system, including surname, given name, given name, number, house number, etc., which expresses the parents' respect for each other. Children's expectations, as well as their own ambitions, interests, etc., are important components of individual culture.
2. Therefore, Chinese people attach great importance to their own names and believe that disrespecting their names is an insult to themselves. In real life, there are often unhappiness caused by inappropriate names. Therefore, Addressing others appropriately and politely is the most basic issue in interpersonal communication. The ancients never called each other by their first names when meeting each other.