You might start by purchasing Lingle's Coffee Cupper's Handbook.
I wouldn't try to host any kind of a cupping event until you are very comfortable doing it, know how to teach it, and have a good idea of what it is you're trying to accomplish by doing so.
Cups, spoons, grinder, a way to boil water, timers, cupping sheets.
Isn't that roughly the equipment list that you've observed at the cuppings you've attended?
Agree with Matt, by the way. There's actually quite a bit to doing it right. I had a chance to attend Counter Culture's "Cupping Leaders Lab" class a few months back. It was a good lab that took several hours to cover most of the material to help us lead a cupping. I found it quite useful. Maybe there's something similar in your area?