The moon has four phases: The new moon, first quarter, full moon, and last quarter. The quarter describes the stage of where the moon is in relation to it’s cycle. The first quarter of the moon phase would put the moon 1/4th of the way through it’s cycle.
The moon’s cycle goes from: new moon —> first quarter —> full moon (2nd quarter) —> third quarter —> then begins again as the new moon.
Before it gets to the first quarter the moon has to begin it’s approximate 29 day cycle somewhere, it begins as the new moon, the first phase of the moon cycle. The easiest way to know if the moon is a new moon is if you see no moon at all. The new moon is actually in a position that is between the sun and the earth so all of the sun’s light will shine on the side of the moon that we do not see from earth, this is why it appears that the moon is not there. Think of it as if someone was standing in front of your light source, your light would be blocked and a shadow would be cast where the light “should” have been.