Apache or nGinx?

that's all fine..

you can enable php-fpm at any time.. you should also consider:

a2dismod php7.3 mpm_prefork
systemctl reload apache2
a2enmod mpm_event (or mpm_worker)
systemctl restart apache2

you'll get warnings/errors on the first reload as no mpm_prefork/worker/event module is enabled. that's fine.

you get the cert warning because the one generated during the tutorial is a self-signed certificate.
you can replace it with a fully trusted purchased certificate, or a letsencrypt certificate.
using the letsencrypt certificate on the control panel is a little more involved.
https://www.howtoforge.com/communit...ts-encrypt-free-ssl.75554/page-16#post-386870

you can also use the same certificate to secure pure-ftpd, postfix/dovecot, monit (if used)
https://www.howtoforge.com/communit...ovecot-tls-pure-ftpd-monit.75546/#post-355701

 

1. Those are normal. I assume they are because of ISPConfig sets things up itself, so just ignore.
2. Certificate does not certify IP-address. So if you access site with IP-address, no certificate applies. Previous discussion on how to get certificate for ISPConfig panel and applications:
https://www.howtoforge.com/communit...el-setup-ssl-email-billing.83333/#post-396618

 

it gives : ./le4ispc.sh: line 28: certbot: command not found
and actually running certbot on command line gives not found error

 

is it possible to run some update script to reflect new hostname all over setup??

 

ohh... so setting up certificate wont help untill i m using actual domain.. right?