Try this chicken recipe. I use breasts but I think the cut is a personal preference. I have grilled it, air fried it, and baked it. Grilling is messy but tastiest, followed by air fryer. Baking is fine but I like the char the other two methods achieve.
https://foolproofliving.com/greek-yogurt-chicken-marinade/
You can make it and store in aluminum pans to keep it warm. Add a salad. You can make your own on grab some bagged ones from the store. Or do some oven-roasted veggies on a sheet pan and make some baked mac and cheese for a side. Easy peasy.
Or if you don't want to cook at all, you can grab a few rotisserie chickens and sides from costco. Or any of their prepped food. It will be cheaper than catering. You just need to heat it up. Their chicken taco meal is enough to feed 4-5 folks and comes with the meat, tortillas, slaw, limes, salsa and sauce. You could buy several of those, heat up the meat and tortillas, put everything in bowls and plates and have a taco bar.
A homemade taco bar is another easy option. Good luck OP.