The phrase "complete novice" means someone who has absolutely no experience or knowledge in a particular subject or activity. They are completely new and unfamiliar with it. Full definition
At this point, I should mention that I'm an almost complete novice to the world of monster hunting. (videochums.com)
He literally has put complete novices in charge for the last 4 years. (sbnation.com)
Leading the committee in training shooters in the club from those who were complete novices at the sport up to those who had shot for years before, devoting hours away in the process. (sport.ox.ac.uk)