So imagine you live in a big world with lots of countries. France and New Zealand are two of those countries.
French New Zealanders are people who have a connection to both France and New Zealand. Maybe they or their family members are from France but now live in New Zealand or the other way around.
They might speak both French and English, which are different languages.
French New Zealanders might eat different kinds of food than other people in New Zealand because they like French foods like croissants and cheese.
They might celebrate different holidays than other people in New Zealand because they also celebrate French holidays like Bastille Day.
So in a way, French New Zealanders are like a special mix of both French and New Zealander cultures.