Using first names when addressing certain individuals, like your boss or professors, can sometimes be viewed as disrespectful. It's important to recognize the context and the relationship you hold with these individuals. Until you understand what is deemed respectful within that context, it is wise to be cautious.
In professional or academic environments, maintaining a degree of formality can help foster respect and clarity in communication. By adhering to traditional forms of address, you can avoid potential misunderstandings and demonstrate consideration for social norms.