My Adobe Express free trial was charged $9.99 automatically. I forgot to cancel it and didn’t intend to continue the subscription.

for others, you have to fix payment problems before you can cancel.

make sure you're aware of the cancellation terms by selecting your plan type (at the top of the page here), https://helpx.adobe.com/manage-account/using/creative-cloud-subscription-terms.html 

for info on how to cancel your subscription, this page describes the few steps involved, https://helpx.adobe.com/manage-account/using/cancel-subscription.html

if you want to cancel but are unable to follow the steps described in the "how to cancel page", you probably have a payment error that you need to repair before cancellation is allowed, https://helpx.adobe.com/manage-account/kb/fix-failed-missed-payment.html

Hi ​@abdoubdm - thanks for reaching out! 

Since this is a public forum, we can't discuss any account related information here. We would recommend you contacting our support team and discuss this in detail through a private chat session: https://helpx.adobe.com/contact.html

Click on the chat icon on the bottom right of the screen to get started!

Rose