Crosswordiee.com

% replaces any number of letters (la% - lake, lamp)_ replaces one letter (ca_ - car, cat)

Crossword clues for Story's first word:

TWAS: First word in a story from Clement Clarke Moore
ANDIT: First words of the Christmas story: Luke 2:1
ONCE: Story's first word
ONCE: First word in children's stories
ONCE: First word of many bedtime stories