I learned of the contest here, and it has already been removed from the Writer's Digest website (see the current contest here), so I don't know all the contest details. I don't know if the sentence provided was intended as the first sentence of the 750-word story writers were to submit, but if it was, it stunk.
"It was on a bright, starry night that the traveling circus rolled into town."Here is is again, revised into a better opening sentence I might actually use:
On a bright, starry night the traveling circus rolled into town.