my card is getting declined for some reason it’s saying is because of a subscription but i don’t have any

Hi gab--10,

Thanks for visiting the Apple Support Communities to get help updating your payment method. If you receive an error that the payment method is declined, you can learn what to do in the Apple Support article If your payment method is declined in the App Store or iTunes Store - Apple Support. You should not need to cancel subscriptions to add a new payment method, as you would need one on file already. In that instance, add the new payment method first, then remove the previous one: If you need to change or update your Apple ID payment method - Apple Support

Regarding the subscription, you can verify your Apple ID is not currently enrolled in any, and cancel them if you are, following If you want to cancel a subscription from Apple - Apple Support. Note that if you are the family organizer of a Family Share group, everyone's subscriptions and purchases bill to you, not just your own.

Best!