From the owners manual:
https://www.tesla.com/content/dam/tesla/Ownership/Own/Model 3 Owners Manual.pdf Page 107
Recent, Favorite, Home and Work Destinations
When you touch Navigate on the map, a list of Recent destinations appear and you can easily navigate to any recent destination by selecting it from the list.If you frequently drive to a destination, you may want to add it as a favorite to avoid having to enter the location's name or address each time. When you add a destination as a Favorite, you can easily navigate to it by touching Navigate > Favorites and then selecting it from the list of favorites.
To add a destination to your Favorites list touch its pin on the map, then touch the heart icon on the popup window that appears. You will be prompted to name the Favorite. Enter a name (or leave as-is to accept the default name), then touch Add to Favorites. The heart becomes solid gray and the destination is included on the Favorites list.
To delete a Recent or Favorite destination,touch and hold it down briefly, then touch the X that appears.