Creating a fictional character from scratch is no easy thing. They must be able to propel the story and still sound like a real person. Below are a few links that may give you a start or could help you fill in something about your character. You won’t need that much depth with all your characters but definitely the protagonist(s) should be a well-rounded personality with identifiable qualities.
Cantrell’s 16 factor personality analysis Table 1 about half way down the page.