Hello Brace1!
Welcome to and thanks for using the Apple Support Communities!
I understand from your post that you use PayPal to pay for your iCloud storage, however there was a problem processing the payment.
Make sure the message you received was from Apple by following the guidance in this article called, Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams.
If the message is a legitimate message from Apple, take a look at this article called If your payment method is declined in the App Store or iTunes Store to see what to do in this situation, and if necessary, contact Apple Support as recommended at the end of the article.
Kindest Regards.