A square is a two-dimensional shape, so it does not have volume.
To find volume, you need a three-dimensional shape.
If you meant a cube, use the formula: volume = side × side × side.
If you meant a square-based prism, use the formula: volume = area of square base × height.
For a square base, area = side × side.
So for a square prism, volume = side × side × height.