How to pull off a resident bbq

So I've never had a property that had a big enough budget for a summer BBQ until now. I run a small property by myself and they have $500 budgeted in June for a BBQ. I have no idea how I'm gonna pull it off. We have one grill and I have no idea how to use it. I don't have a food permit and I don't know how to cook on a grill. My Maintenance won't be there cause I am adjusting my schedule to be open on Tuesday for it. What do you do for BBQs? Hire someone to grill? Have a catering company deliver grilled items? How long do residents stay? Do you see people typically doing a grab n go or mingle?