A:AnswerYes it should work you just redeem the code on your Xbox S or X models or even directly to your Xbox account and it works. For your Xbox account you have to be register or just register and creat a new account is free.
A:AnswerThe 12-month subscription only begins when you ACTIVATE the card. I typically keep some extra cards on-hand in order to help ensure that I don't let my XBox Live membership expire unexpectedly.
A:AnswerXbox Live Gold Membership is tied to the account it is purchased/ redeemed on. If everyone in your family plays on a single account then you're all set but if they play on different accounts then all accounts will require gold to play online.