I installed renewed SSL/TLS cert in WHM/cPanel of the domain :
yyyy.city/www.yyyy.city
This is needed also for all subdomains - show Cert expiration - well???? do this? How to set wildcards so subdomains Not needed the same process???
If you are looking to automatically secure your sub-domains then you will have to enable AutoSSL feature from WHM Home »SSL/TLS »Manage AutoSSL. If you are using shared hosting then you will have to ask your hosting provider to enable AutoSSL for your account.
I think the question if I'm reading correctly is more along the lines of how to obtain wildcard certificates for AutoSSL. The Let's Encrypt provider will install Wildcards for Wildcard subdomains, if that's what you're looking for. Information on this can be found here: The Let's Encrypt Plugin | cPanel & WHM Documentation