Seasonings are usually: salt, cumin, pepper, pepper, honey, cayenne pepper. A small amount of ground sesame seeds and peanuts, barbecue sauce (pasta sauce, hot sauce, etc.), ketchup, and butter/oil. And a small brush for brushing oil and sauce. Small mixing bottles for spreading the seasonings evenly.
Cut the ingredients in advance, cut into small pieces and marinate. Refrigerate. Purchase skewers and thread them in advance. Place in a Styrofoam box and keep cold.
The ingredients are calculated at half a pound to eight taels per person. If you're a young person and the majority are male, buy more meat. Make the quantities larger. For middle-aged and old people, buy less meat and more flavor. If you have to buy your own charcoal, you should also buy half a kilogram of charcoal per person.
I don't know if a grill is necessary. A small grill is usually enough for 4 people. Bigger grills serve more people. However, the grill speed is slow, so if there are too few grills, they won't be able to serve you fast enough. You'll need to have some clips and a wire mesh. Depends on what you're eating.
And drinks. Beer, liquor, coke, etc. You'll have to calculate this separately. Bring some plain water. Use it to dilute the honey, etc. If necessary, you can also make a soup. You will also need to buy paper plates and cups, disposable chopsticks, spoons and napkins.
Don't forget to bring paper, alcohol, and a lighter to start a fire.
That's all. Hundreds of people. That's a lot of people. That's enough to keep you busy. One suggestion, split up into groups. Buy ingredients and prepare them in groups.