This is a comedic novel that is character based.
Even a character-driven story has conflict; that's what keeps a story moving, making us care what happens. You may have several conflicts going--character against character, character against environment, character against self. Pick one that has the most depth, one that you feel most attuned to, and make that the focus of your query. Also--as leslee said--you cannot simply declare in a query that your story is comedic: the query itself must impart a sense of that humor.