When notes are written above or below the staff, ledger lines are used to extend the range of the staff. As if the staff had more than 5 lines. To make a ledger line, draw a short line parallel to the staff.
If you know the English Alphabet, you already know the musical alphabet. The musical alphabet is the first 7 letters of the English Alphabet.
A B C D E F and G. That's it.. There are no other note names. Once these 7 note names are used they start over.