The most important effect of the Moon is the way it stabilises our rotation. The Moon is smaller than the Earth and it takes 28 days to travel around the Earth and it is roughly spherical .We only see the part of the Moon that is lit up by the sun. If you need more information go to this websitehttps://solarsystem.nasa.gov/moons/earths-moon/overview/
The Moon is the most significant contributor to the tides on Earth and the Moon creates the tides. If there is no Moon, all sea life and fisherman would be affected. The closer the Sun and the Moon, the higher the tides will be.https://science.nasa.gov/science-news/science-at-nasa/2000/ast04may_1m
What would happen if there was no Moon?
The most obvious fallout of an absent Moon would be the tidal change. If the Moon wasn’t affecting our oceans, the tides would be about a third of the size they are, also the Sun would take over the tidal changes. However, the Moon is also helping to slow down Earth’s rotation.