Billing
I’m trying to update an app and/or get a free app and it’s asking me to update my settings and even after I do it says I have insufficient funds when I know I have enough. I don’t know what to do
What is the exact text of the message/prompt that you are getting ? When you have a payment method on an account it has to be a valid card and pass the iTunes validation, whicy may include being able to apply a temporary store holding to check that the card is active.
If the card is not accepted try a different card or see if you can remove it : Change or remove your Apple ID payment information in the iTunes Store - Apple Support
If you don't get the 'none' option on the payment details screen : Why can’t I select None when I edit my Apple ID payment information? - Apple Support