why i need credit card i not buy anything
Why update something like Facebook need my payment info
If you have a credit card entered for anything Apple may require you periodically verify it is still valid and correct. I don't use Facebook but some apps may have associated subscriptions of in-app purchases even if the app itself is nominally free. You can try setting your payment to none and see if that works.
Removing a credit card from an account - Change or remove your Apple ID payment information - https://support.apple.com/HT201266 - More information at: https://discussions.apple.com/thread/3251676?answerId=15891166022#15891166022
If you can‘t choose None when you edit your Apple ID payment information - https://support.apple.com/HT203905 - also make sure you don't have any active subscriptions or are set as the Family Organizer for a Family Sharing plan.
You can only choose None when you set your payment method up from the iTunes Store, App Store, iBooks Store, or Mac App Store. None is not an option when you use the Apple ID account page to set your payment method.
Sign in with your Apple ID - https://support.apple.com/HT204053 - "When you sign in to the iTunes & App Store for the first time, you might need to add a credit card or other payment information to help secure your account." 20170919
iTunes [Store] Support - Use this form for assistance with account and billing, code redemption, or purchase questions - https://ssl.apple.com/emea/support/itunes/contact.html