How can I cancel my subscription to this software, I pay by PayPal, and do not use the software, and do not want to keep paying for it.
It sounds like you may be looking to cancel your personal Creative Cloud subscription. I'm not personally familiar with the process, but I did find the following help article that may be of some help.
Cancel your Creative Cloud membership
Which software are you referring to? Are you a Creative Cloud user looking to cancel your personal subscription, or are you looking to cancel a Marketing Cloud contract?