What should i cook for my family?

My cousins and i have to cook a meal for our parents at the beach and we always have a hard time deciding on what we should cook. so does anyone have any ideas that's pretty easy that kids can make.... the ages 18 14 and 10 so we can use a grill and just about any other cooking utensil. we have all ready done hamburgers, hot dogs, pizza and breakfast food. also no sea food cause we don;t know how to make that.