Nintendo online - individual or family?

Just got a single switch 2 console for the family. It has one account (email and all that) with multiple profiles (name and avatar only) We will not be getting additional consoles.

We want to play the older games, and I have 2 kids that want to play split screen at times. Nothing actually “online” as they’re too young to be playing with strangers.

Do I need family or individual membership?