How can I cansel risk-free before my trial period expires?

Please see here: https://helpx.adobe.com/stock/kb/cancel-membership-subscription-stock.html

or you can contact Adobe customer care. Adobe customer care can be contacted by beginning a secure chat session at https://helpx.adobe.com/contact.html?rghtup=autoOpen. If the chat window fails to open, or is non-responsive, use a different device to start the interaction.

(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
https://community.adobe.com/t5/account-payment-plan/how-to-contact-adobe-support/td-p/11843852)