Ringback numbers are not available publicly but can be accessed by calling your phone provider and requesting the ringback number for your area. Another option would be to call your phone number from a different telephone.
Most phone companies have ringback numbers you can dial that call your phone and make it ring. Telephone operators use this to check whether a phone line works after being installed. To prevent abuse, these phone numbers are not usually publicly available. However, you may call your phone provider and request the ringback number, and they may be able to give it to you. Dial the number, then hang up and your phone should ring.