Inside a black hole just means inside its event horizon. The singularity can still be arbitrarily far away from that horizon (if the black hole is correspondingly large). The volume enclosed by the event horizon may be larger than our cosmological horizon (i.e. how far the speed of light allows us to see, given the finite age of the universe.) And the singularity of a black hole isn’t “where”, it’s “when”. The singularity of a black hole is in the future of all particle trajectories inside the event horizon.
If the universe is bounded by regions that are further away than the speed of light has time to reach us then that would be an ideal place to look for a singularity. unfortunately it is unmeasurable since so far the speed of light is a hard boundary for what we can measure.
2. If we are inside a black hole, where is the singularity?