There are three and Fanfiction is known for One of them. And that is the one we start with.

First person.

I personally stop reading as soon as I see First Person. I don't use it, unless I write a diary entry or something these lines. I associate it with bad Fanfiction and bad writing in general. Though, from what I've heard, there are Fanfictions and books written with it that are very good. So, I would say first person writing is the perfect example for "Easy to learn, hard to master." It is a good entrance to write, because it is so easy, but it is hard to write something great with it, hence the floods of bad written pieces using this point of view, which causes the negative association.

Now, for the handful who don't know what I mean with first person, I know you exist, this point of view is written from the view of one character. Essentially, you are the character. An example sentence would be, "I jumped over the floating isles." The 'I' shows that the sentence is told from a fix characters perspective, not a narrator or a different person that describes what X does.

This point of view is supposed to be very restricted, as the author can only write what the character knows. This means, lets say you write something, like Harry Potter, where a character gets introduced to a new world. This character could only describe how things look, while a different character who is familiar with that world could name them and explain what these things are.

The next point of view is not common in fiction, instead it is used in manuals and guides, like this Fanfiction writing guide! It is the second person. In this view point, the reader is told what happens. The example sentence would be, "You are jumping over the floating isles."

Like you can guess, this view point is very difficult to write, hence it never really being used outside of stuff like manuals.

The last point of view is third person. In this view point, a narrator tells the story, no figure in the active events, someone 'watching above or on the side', as one of my teachers said. like I said, the first person is limited to the knowledge of the character the view point belongs to, third person can either be omniscient, all-knowing or can be as limited as a first person view point would be. Or a mix and hint at things. What ever dose of knowledge and awareness you write, keep it consistent. When you write all-knowing, don't change suddenly to a limited awareness and back like you please. Oh, and omniscient narration is very difficult to make entertaining, as it could appear like constant info dumping or just boring in other ways. The example sentence would be, "X was jumping over the floating isles."

Apropos consistency, don't switch between the point of views. I do not mean it in the sense that, when you write in first person to only stick with one character, but that you shouldn't switch between first, second and third. Pick one, stick with it all the way though. If you have to switch, rewrite the already written text.

Though, for the first person switching, try not to switch every few sentences. I saw many Fanfiction writers who switched every sentence, it was so annoying to read! Another annoying thing I see Fanfiction writers often do is switching the kind of point of view, meaning between first and third. heck, I found someone who switched in the text. Not writing one paragraph in third and the next in first, literally in the text. Keep it consistent. And, back to the original topic of this paragraph, try to hang with one character for a long time, too frequent switching is annoying and rips the reader out of the immersion.

There is a different type of Narration, more specifically a system of Narrator categorisation, but I barely understand it myself, so I will not explain it now. At least not yet. I linked a video for the people interested.