Matter getting close to a black hole can get heated up a lot and emit a ton of energy that we can see. It's only after it's fallen inside the "event horizon" does the radiation not have enough energy to escape the gravity well of the black hole. The neighborhood near a black hole can be quite lively and not at all dark.
Also please beware of the oft repeated descriptions of the "infinitely dense singularity" at the center of a black hole. All that means is that our current theories have no clue what's happening. Most reputable scientists (i.e. the ones I agree with) assume that our theories are just incomplete and that something exists at the center of a black hole to prevent an infinitely dense point ... we just don't know what it is yet.
This is my from my favorite (short & readable) essay on black-holes:
The problem is that infinities never exist in the real world. Whenever an infinity pops out of a theory, it is simply a sign that your theory is too simple to handle extreme cases.
https://www.wtamu.edu/~cbaird/sq/2013/09/13/does-every-black-hole-contain-a-singularity/
Disclaimer: Sadly I am not an astrophysicist nor have I ever been inside a black hole.
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