What does jacob imprinting on renesmee mean?
it means that they are meant to be toogether. Jacob automatically is in love with renesme forever and he will never be able to love anyone else. He also feels obligated to protect her. since renesme is way younger than Jacob, he must stay in the warewolf group and not retire from it because when he is still part warewolf, he won’t age. So eventually Renesme will be able to catch up to him and they can live together happily.