Creative Cloud does not use serial numbers like the older Creative Suite products do. If you have some form of a serial code it is likely only to enable your subscription thru your account when you sign on thru the desktop manager.
Creative Cloud for desktop
Sign out, Sign in | Creative Cloud desktop app
There is a product called "Adobe Creative Cloud Individual"
activate it from the link below
It has 24 codes.
I do not think you know about this product.
Adobe is No customer center email?