The universe is everything by definition. It is closed system -- as we understand it... That anything outside our universe is meaningless in ours.

Still, does it make sense to ask what is outside the universe?

Do we see say that because with our current level of technology, we cannot leave this universe? So it is safe to assume that there's nothing, but could we assume that there's something?

I think the Universe is endless, I have know idea how there is that much room to hold all that. I think as people, we always have a space, border, or limit, and hard to believe in endless.