MacOS Mojave version 10.14.6 - Compatible with Adobe Creative Design 5.5 - for disc install

Not Compatible.
CS5.5 compatible old OS X 10.5 to 10.8.

The sale ended 10 years ago.
Even if you see it now, it will not be a genuine product.

First... Transfer (selling or giving your software away) https://helpx.adobe.com/x-productkb/policy-pricing/transfer-product-license.html
-you may NOT sell or transfer an Education serial number

Second... https://helpx.adobe.com/premiere-pro/system-requirements/earlier-versions.html

Third... Apple did not maintain backward compatibility, so try this to install old programs
https://helpx.adobe.com/creative-cloud/kb/install-creative-suite-mac-os-sierra.html

And finally be VERY careful buying on ebay... lots of real looking fakes, or company site license programs sold illegally

-Warning that software is not genuine http://www.adobe.com/genuine.html
-http://prodesigntools.com/dont-buy-adobe-software-on-ebay-craigslist-or-amazon-marketplace.html