u/Hopeful-Wealth-8823

I tried writing a campaign before and it was very lack luster. I'm trying to write a new one for a different game and I'm looking for advice. I have the setting, I have a monster, I have a ton of premade character sheets.

I'm not good at making mazes/labyrinths (required because of what its based on) and I'm not experienced enough to think of what else I should do. It's meant to be a one-shot so I can get the hang of it.

Any advice to help a nervous newbie?