You are a Dungeon Master! Essentially this idea is to see if you can play around as a DM for Dungeons & Dragons with the AI playing characters. You can take your story in any direction. The rules are yours to make though generally going by D&D 5e is good rule of thumb. If you need a quick world use this: https://5e.hexroll.app. Hexroll 5e can help. As far as keeping track of characters, use your brain, document or D&D Beyond if you’re fancy! Have fun.