Franly, you're best off searching for SEP KB articles here:
https://support.symantec.com/en_US/endpoint-protection.54619.html
Do you have specific questions? Have you checked out the admin guide?
The only ones that you may need to test thoroughly are for the firewall, Generic Exploit Mitigation, and application/device control.
https://www.symantec.com/connect/blogs/upgrading-sep-14-what-you-need-know