Hey,
There are some toothpastes available in market which claim to whiten your teeth. Also you can use some home remedies like rubbing the skin of banana, applying baking soda paste etc.
However, these might not be very helpful. So,get that whitening done from a professional like Dentist.
Next Steps
Visit your dentist.
Health Tips
If you are using home remedies, check carefully the procedure before trying.