I’ve done open mics, storytelling, and I can agree that mostly the crowd is welcoming. You may get a few self-absorbed shits that are only there for the strokes, and these can usually be ignored. Which really pisses them off so is worth doing on those grounds alone. Consider using a nom de guerre - at least at first. It’s an effective way to manage the feeling of threat to one’s personal identity. A ‘poetry name’ is very traditional so I think you are in good company if you choose to use one.