There are two characters that every story needs; a protagonist and a narrator. Both can be the same character. The protagonist I will go over later. The narrator I will go over today.
The narrator is whoever is telling your story. Is it the protagonist, the protagonist’s friend, or just some random dude who just happens to always be there when cool things happen? This is what you have to decide first. Your narrator can literally be anyone. This is the only type of character where they don’t even have to be a character. The narrator can simply be a disembodied voice and it doesn’t matter much.
But I highly recommend that you at least try choosing a character to be your narrator because having your narrator be more than a disembodied voice can make your story more interesting. Is your narrator hiding anything from the readers? Is your narrator biased about anything? All of these can change the apparent flow of your story a lot, and this change is usually a good one.
If you want your narrator to be a disembodied voice that is fine as well. Then you just have to decide whether to make them omnipotent or limited because you will be forced to write in the third person. The character choice is usually first or second person.
You can have more than one narrator. This happens a lot in fantasy stories and stories that take place over a large geographic area. To do this choose a character from each of the major subplots in order to keep your readers informed about what is going on in each subplot. Just avoid head jumping and you will be fine.