So there was no time and no space and then the Big Bang, the Universe springing from a singularity. Now inside our Universe we have black holes and in black holes there is a singularity . Universes inside universes an infinite amount of Universes , now each and everyone of these Universes is the only Universe in existence which sprung from a singularity.

So there was no time and no space and then the Big Bang, the Universe springing from a singularity. Now inside our Universe we have black holes and in black holes there is a singularity . Universes inside universes an infinite amount of Universes , now each and everyone of these Universes is the only Universe in existence which sprung from a singularity.

A singularity is simply where our current theories cannot explain: They are not necessarily infinite, but may lead to infinite quantities.

Most physicists today do not believe any singularity within a BH leads to any infinite quantities.

Plus the BB singularity, was a singularity OF spacetime, while any BH singularity, is a singularity IN spacetime.

Anything else, like the BB singularity being a white hole from another universe, and BH singularities, leading to other universes, is just speculation...interesting speculation, but essentially just speculation.