First BDSM shoot next week: how do I prepare and stay safe?

My first BDSM shoot is booked for next week. Rope and a bit of latex. I’m equal parts excited and terrified, and I’ve genuinely never modeled before. What do I need to sort out ahead of time, and how do I stay safe on the day itself? Anything you wish someone had told you before your first?

— Nervous but excited.