You can reconnect with a person, Page or group that you unfollowed by following them again. Only you will see the change. The person, Page or group won’t be notified that you followed them again.
To follow a person, Page or group from your News Feed preferences:
  1. Click Reconnect with people and groups you unfollowed.
  2. Select a person, Page or group.
To follow a Page or group directly:
  1. Click Liked (on a Page) or Joined (in a group) near their cover photo.
  2. Select Follow.
To follow a person directly, click Follow near their cover photo.