You’ll probably need to scope out the Airbnb kitchen to see it it’s well equipped.  If you happen to be near a Trader Joe’s, there’s lots of frozen sides that don’t need a lot of preparation and are fun. Finger food is good as well, as you don’t need the formality of fancy table settings. Another of my go tos are the jalapeño popper recipe from Sunny Anderson. (Food Network). You can finish off with an ice cream sundae bar. 

I make this every time we have a group trip, and it slaps. People love it, and it's so easy to make. Sometimes I serve over mashed potatoes, sometimes egg noodles, sometimes polenta. Dealer's choice! Leftovers are excellent the next day as a sandwich on a potato roll. Extra points for crushing up some Cool Ranch Doritos as a topper.

I optimize for apps. Everyone loves apps, and will fill up on them so much that there will be no need for dinner. 

So... a shitload of cheese, queso dip and guacamole, baked brie, and a bunch of stuff you could throw in the oven and serve (potato skins, mozzarella sticks, etc.)

Baked potato bar is also a very economical and filling way to feed a lot of people. 

Damn that's a lot of people! Tell your family to chip in :P But seriously, for a lot of people (with no dietary restrictions) I would say some sort of casserole/lasagna type thing.  I would try and find things in the supermarket to help you make dinner "semi-home made" like bagged salad mix, premade meatballs/pasta sauce, frozen veggies that you can just add a little butter and seasoning to or even a few rotisserie chickens. Mashed potatoes are always a favorite too and are pretty easy to make. 

I love to cook!  I can totally help you!  Omg I have a few recipes that are awesome for groups!  Im joan foos.  Text me?  Email me?  Id love to give u my favs!  They are good.  Cornbread soufle. Great delicious sidedish everyone will want the recipe!  I have great easy pasta bakes!  Ground turkey pork or chicken.  I mix pork and chicken usually.  Thats yummy!!!  Id love to help!

In March I am renting an Airbnb with my family. The last time I did that was for Thanksgiving. Also I only really know how to cook Thanksgiving food for a large group of people. So what is your go to meal when you have to cook for more than three people?

I need to go to meal for nine people