There are three points of view- First Person, Second Person, and Third Person

First Person
Using "I"
Example: I looked through the window, prepared to jump.
Second Person
Using "you", rarely any story is written from this point of view
Example: You looked at the window, deciding whether to jump or not.
Third Person
Using "he/she", and the narrator usually isn't part of the story
Example: He looked at the window, prepared to jump.
If your story involves switching a character's point of view, don't do it in the middle of a chapter. Also, begin each chapter with just the person's name, such as "Lily". Don't put "Lily's POV".