Can you explain purgatory and how to get out?

We have the concept of purgatory. I read in different places that purgatory happens after death. But what should be stated clearly is whether they mean physical death or spiritual death when discussing this topic. Nobody on Earth is wise enough to explain what happens after physical death, so I'm interested in this concept after spiritual death while still alive, because that's what people care about to stay healthy and alive. Can someone explain how a person goes into purgatory, and how to get out? I'd prefer an answer from the Catholic religion.