With observation and measurement over huge areas and eons of time, we have never found empty space. We have never found a perfect vacuum.
However, with the classical point of view, space is empty. The problem is that to find it, one has to go several cosmos diameters out from here, to find it. This is because mass, very frequently emits radiation. The reason it emits, is because mass can only stay stable as mass, at certain energy levels. They call this the quantum effect. This makes the mass act like an energy spring. If you shine radiation on mass, some of the mass, will re-emit radiation, because not enough was absorbed, to take it to the next higher level. So it emits, and returns to it's previous level. To stay stable. After all these eons, we have a background of these "orphan" emissions....which was called static. This energy is only temporarily occupying space, it does not come from space. These orphans can superposition for short periods of time, giving a field density. We measure this as spurious or fleeting spots of energy.......which can be measured as temperature also.
With classical theory, space has always been here, emptiness needs no creation. Empty space is the only thing that can fill infinity.
However, modern theory has a much different point of view.
In the future we might be able to build a container which can be made, to have no particles within it. But, it will not be a perfect vacuum, because we can not keep fields and emissions out of it. So it will still be occupied. With a physical presence.