Assuming you are in the Northern Hemisphere, the North star is not visible south of the equator.
In fact, there is no star that always indicates north OR south in the Southern Hemisphere. But, you can use the Southern Cross and the pointer stars as a guide. Face the lowest pointing star and you'll be facing south; turn around and you'll have found north.
By the help of the North Star.
Take a magnet suspended on a thread, it will show you the north direction.
The North Star can help in finding the Northern direction at night without a compass.
If you’re having trouble finding the North Star as it is not one that is very distinct, you have to first locate the Big Dipper or Ursa Major constellation.
A line drawn through two stars of the Ursa Major point to the North Star which is located at the tip of the Ursa Minor’s handle. The North Star is located in the same direction as that of the polar axis and so it does not vary. For a very long time the North Start was how sailors at sea determined the direction they were headed in.