The Moon is the natural satellite that revolves around the Earth. It has no atmosphere, no water, nor does it have any weather. On Earth we only see one side of the Moon because the moon rotates at the same rate that it revolves. A bluemoon occurs when there are two full moon in one Earth month. Since a lunar month is roughly 27.3 days and an Earth month is 30 or 31 days it is possible, but happens very rarely.
Nothing physically happens to the moon, nor does the moon turn blue.
When the Moon revolves around the Earth it gets lit differently by the sun, causing the phases of the Moon. When it is half way lit on the right side it is in its First Quarter. When it is on the unlit side of the Earth it is a Full Moon. When it is half way lit on the left side it is in its Last Quarter. That cycle is processed every lunar month.