This Blender Black Hole Tutorial is more more of quick high level tips rather than making a perfect simulation of a black hole.

Many others on YouTube have better tutorials for that such as this one by Alaskan FX.

For me – it’s more about getting something up and running that works for the frame fast. When you have a larger story to tell – try to not get bogged down in creating “perfect” effects or assets. If it works in the frame, GOOD! Move on 🙂