Lyric discussion by gymnopedie 

Cover art for Milord lyrics by Edith Piaf

soumik! You need to look up how french negatives work! Ne...que means "only"

Donc, le phrase "Je ne suis qu'une fille de port, qu'une ombre de la rue" means "I am just a girl of the port (a prostitute?), only a shadow of the street.

@gymnopedie Yes, this song does highlight the perils of Piaf's earlier life, being involved in such business.