Yes and no. Your character history will be a modern human on Earth, but on entering the moon, you will enter a typical DnD sword and sorcery setting with modern-day human knowledge.
Yes, some people entering the moon are gifted with magic. Rules are mainly unchanged, but some setting flavour is put on things like Warlock patrons. Some spells are disallowed due to the setting, such as flight and teleportation magic to make the campaign work better as a survival and exploration setting.
Everyone WAS human. Some people are transformed on moonfall. This obviously means there are no non-human societies yet.
Yes! The advantage of the modern person in fantasy world exploring trope is you don't need fantasy world or setting knowledge.
No. This setting is designed for a large cast, of which a handful 4-6 will be playing each week. Some events will overlap, but the story is moving forward, and each game will impact the world and uncover more mysteries. I'm still working out a schedule with organisers, but I want this to be an easy game to drop in and out of. Because a big part of the campaign is exploring, finding new information and dealing with shared threats, you will be interested in other parties' events.
No. I provide maps and a general sense of combat, often scribbling on paper or provided map handouts but I do not use mini's in battle, preferring a more free flow RP heavy combat.