There comes a point when getting to know your characters isn’t all that useful anymore. Something has to happen to them in order to get the story moving. That’s where plot comes in. There are plenty of plots out there and even taking one that someone else has done doesn’t mean that your novel can’t be fresh. Look at how many times Cinderella has been redone and re-imagined. So don’t be afraid to write a new take on Little Red Riding Hood if that’s what strikes you. But in case that doesn’t, there are Georges Polti’s Thirty-Six Dramatic Situations. I linked to the Wikipedia page, which lists them all out, but if you need more explanation for any of them, there’s a link at the bottom of the page for the full text of his work at Internet Archive.
Thirty-six is also not a definitive number. The Tennessee Screenwriting Association came up with twenty. And I know of another site that has 32 RPG Plots, which is pretty great, but focuses on plots that work well in roleplaying games, so they might not all be the greatest for a novel. But you never know where inspiration will come from.