You have elaborated the list of characters and know all of the main characters intimately. Now that all of them are real to you, the next step comes naturally: Who is telling the story?
You must never confuse the author of the novel (you) with the narrator (your creation). In a fictional story, the author is never the narrator.
If the narrator tells the story away from the characters, you are opting for an external point of view. In this type of point of view, the narrator could be:
Omniscient narrator (ever present)
This is God. It has access to the internal and external world of the characters; it knows their past and future. It is ubiquitous, and may narrate simultaneous events that occur in distant places. It has complete understanding of the story and can deal with many characters at once. It can also form opinions regarding the facts it narrates, even though it might not always do so.
Camera lens narrator
This narrative technique creates the illusion that there aren’t intermediaries between the story being told and the reader. It is similar to when in film we can see the actions of the external world of the characters, but never know what they are thinking, what they feel, their past or their future. It is like witnessing the story as it happens.
It is an omniscient narrator, however it is limited to one of the characters. You will use the third person but you’ll tell the story from the perspective of the protagonist. You’ll only access scenes, which the character sees, what she/he thinks and feels, but not the rest.
If the narrator tells a story from the inside of characters (be it one or several), then you will be adopting an internal point of view. You’ll use the first person, and you’ll see the story through the eyes of that character, and we’ll be able to hear his/her thoughts.
There are numerous combinations that might bring into play different forms on how to tell the same story.