Particularly since you mention having had a card declined that may explain it. The resolution to this issue is often making sure you have entered a credit card or other valid method of payment* even if you plan on using account balance to pay for a purchase.
If there is an option to select "Review" or "Continue", select that and enter valid payment information if required. If there's problems doing this:
On a mobile device tap: Settings > [your name at the top] > Media & Purchases > View Account > Manage Payments > AddPayment Method.
Alternatively this document explains how to 'Add a payment method to your Apple ID' on an Apple mobile device, a Mac, or a PC; click here --> Add a payment method to your Apple ID - Apple Support
More things to try in this 2018 post by Urquhart1244 marked Apple Recommended:
This Apple ID has not yet been used with … - Apple Community
If you continue to have problems contact Official Apple Support - Select your region from the list and then your country from the pop-up window. If you do not see your country, see if there is an "other" listing for that region.
Apple Support
*Payment methods that you can use with your Apple ID - Payment methods that you can use with your Apple ID - Apple Support
