I’d grill, chicken and burgers, premake a bunch of side salads like potato salad, green salad, watermelon salad, etc.
Or a taco bar - make pulled pork in a slow cooker and cook diced blackened chicken breasts ahead of time and serve at room temp, along with taco fixings.
If you want this to be a nicer meal, I’d make two pork tenderloins or chicken on sheet pans (something like chicen marbella) both which can be prepped ahead and then roasted while guests are there.
16 people is just having 2 other families over since you are a family of 6, so really you could scale up on anything that is a go-to for you.