Answer:
it depends on what kind of story you want to tell, or what the message you are trying to convey through the story is.
first person is good for when you want to know all the feelings and emotions of the main character. it rly helps get in depth with that character (tbh its my favorite)
third person is best for when you want to focus more on the actions of the characters. it also lets you stray from always talking about the main character. so for instance, you can sometimes do a chapter here and there where another person, or even the bad guy, is what is talked about in the chapter