Video: Two theories, from the always knowledgable Kurz Gesagt: you die a quick death or you die a very quick death. No one knows for sure but you probably don't want to be the first person to find out. If you do, you'll notice that time moves slower inside the black hole. But once you're in though, you can only go in one direction (towards death) and its gravity will destroy different parts of your body. Or you'll just burn instantly.
In a Nutshell also examines the birth of a black hole (when a massive star goes supernova) and the death of one (evaporation through hawking radiation). The whole explainer video is fantastically done and details terms you're familiar with like event horizon, the singularity, empty space, and so forth in the simplest ways to understand them.