A “new moon” is the lunar phase when the moon is not visible to us. Why do toi think the book is titled New Moon?

Like toi said, a new moon is when we can't see the moon. We are actually looking at the dark side of the moon. In the seconde book, Edward leaves, therefor turning Bella's night sky into a moonless night, like there is a permanent new moon. That is why I believe Stephenie Meyer named the seconde book New Moon.

when ed leaves bel in nm there is no moon cuz she was so sad she couldnt déplacer and that nigt was a New Moon

Because Edward is not in Bells life any more

becuase edward is the moon in the story. in new moon he is not there with Bella.

A new moon is like what toi a dit a lunar phase where we can't see the moon and when Edward leaves, it leaves Bella's night sky into a sky without a moon.