Nintendo Switch Online, a few questions?

Finally got my Nintendo Switch.

However, I do have some questions about Nintendo Switch Online.

So there's an individual membership and a family membership. Since my brother and I use the switch together, I think family membership would be better, right? (We have created 2 users on the Switch, 1 of them is logged into My Nintendo, so to speak, the other one is not, should we also register this?)

And why is family membership only available for 12 months? (this is how it is displayed in the Nintendo E-Shop)

Do I have to get a special card with code to buy the membership, or can I take normal Nintendo e-shop cards?

So if you want to play online with both user accounts, you need family membership. Of course, paying also works with normal prepaid cards. Well, there are also shorter memberships, but 12 months is wonderful, and you can also activate an automatic renewal.

Thanks for the help.

There's online membership, so you can play together. Costs 12 months, 20 euro.