Let's start with what is Universethe universe: Universe the universe is everything that exists - galaxies ->, stars, planesplanets,... -> matter, energies, etc. So Universethe universe is composed of atomatomic components and the energies between them. That means that our Universeuniverse is composed entities "positioned" relatively to each other in some space.
Even if everything is relative and space is infinite -, there aren't any bounds like the start or end of space. How can be this space in nothing? It is supposed to be in something, forming something like atoms are forming complex structures. But if it's in something then where is this something? So that would be infinite recursion and if this recursion ends somewhere it would be again nothing.
Do we exist? If we do, then where?