The start point is the location from which the route begins. In most cases, this is your current location, which is automatically detected using GPS. However, you can also plan a route from a different location by setting any address or map position as the start point.
For details on the available methods of selecting a location, see the article Selecting a point.
After selecting a location, the action menu (a menu with additional options) will appear. Select Set as start point to use the chosen location as the starting point of your route. You can then continue by selecting a destination, as described in the article Destination.