"Accompany Frea to Skaal Village" is an objective in the main quest "The Fate of the Skaal" in Elder Scrolls V: Skyrim - Dragonborn.
With the Black Book in your possession, it is time to head out with Frea. Follow the path Frea takes out of the Temple of Miraak.
Head down the slope of the mountain side you emerge on to the North. You can see a green beam coming from a temple down the slope.
This will bring you to the Wind Stone. A quick visit will make things easier in the near future.
Head back up the slope and continue to follow Frea when she goes across the bridge to the East of the Temple exit.
A short distance from the bridge is the Skaal Village. Follow Frea inside the village and go along with her to her father.