Short answer: Have you ever gotten into an argument with yourself and somehow managed to lose? That.
Long answer: Plurality is a phenomenon where multiple distinct personalities coexist within a single body. Sometimes they get along, sometimes they don't. Some systems are born from trauma, others just sorta happen. Being plural is an experience that varies wildly from system to system. But the important commonalities is that each system member is just as real as the host.
We appreciate your concern. We're sure you have the best of intentions, but being plural isn't inherently good or bad. It's just another way of existing.
As usual, Hollywood lied to you. Being plural does not necessitate an "evil alter" scenario. They can exist, sure, but they're much rarer than you might expect. In our experience, most plural systems we've encountered get along well with others, no matter who's in front.
Whatever terms they ask you to. That said, here's a few common terms you're likely to come across:
Unfortunately, we can't answer that. Just as there are many different kinds of people, there are also many different kinds of plural systems. We can only speak for ourselves, and the systems you know personally probably have wildly different experiences. If you're curious, ask the systems you come in contact with on a regular basis. Be gentle, be sympathetic, and above all, keep an open mind.
See: The rest of our online presence. We're open about our plurality, and we post about it often, especially on the Fediverse.
First and foremost, remain calm. Plurality isn't inherently a bad thing. Your attitude towards your potential headmates will dictate how they act around you. Remember, headmates have feelings too.
We encourage you to study plurality, making sure to keep an open mind. Take a look at the "Further Reading" section below. Keep in mind that your experience may differ from what you hear from other systems. Just focus on finding what works best for you+.
This will be a slow learning process, as you and your headmates learn how to coexist. Be patient. Give yourself time to adjust. This is a marathon, not a sprint.
Haha! This section is under construction! Don't worry, we'll be adding plenty of jumping off points before publishing this page publicly.
We applaud your inquisitive nature!
Please read through the links in the "Further Reading" section above, they might have the answers you seek. If you still can't find an answer, reach out to your plural friends. Remember: Every plural system is different, so any answer you find may not apply perfectly to a given system. Just keep an open mind and treat each system and system member with respect.