You can't copyright the alphabet.
You can only copyright the specific code that makes up your font, for which you need to come up with usage licensing.
You do need to register it before you ever need to go to court for infringement.
I suppose you could give friends and family discounts. But when a friend is so naive as to think you can just whip out ten hours worth of work in 30 minutes or thinks so little of your time that he or...