Dressing formally doesn’t mean to dress well and smartly. An attractive formal dress code is also needed. Because until and unless you don’t dress like the people can capture your view they won’t even give dame attention to your dress code.
So I would advice that for girls wearing a pencil skirt with a beautiful shirt and a pump would make a great match. Or if you don’t want to wear skirts then two set dress ( wide leg pant set) will also works awesome.
So for boys obviously suits are the best( as this was especially for ladies)
Hope I helped you ??