Two issues migrate from cPanel and varnish says not installed

So I am migrating from HostGator shared service to my own VPS and CWP....  I installed varnish in CWP but when I click it, it says not installed.  CLI shows it is wondering why this shows this?


Also, I copied all files to my PC and transferred them to my new server under public-html of each domain.  I chose to do this because when importing via restore it creates subdomains and that's not how I want it setup.  I want each domain separately setup as its own domain.  Anyways, when I copied everything it shows a 502 error when going to my domain or my domain.com/wp-admin....  Anyone have any idea what I'm doing wrong or what I need to modify?  Do I need to change wp config to new database?  Since I'm moving to a new server will there be other files I need to modify the configuration on?  I can't use the CWP server migrate feature I've tried but since my service is shared with HostGator I don't have root access.  I'm considering upgrading to a VPS on their end just long enough to be able to do this to make it easier if it will be more simple of a process.

you should check the error in the error logs...or you can remove varnish if you are not sure if this is varnish/php-fpm related.

also since you are doing all new its recommended having each domain as a new account to make them more separate and more secure

That's fine and I don't have an issue with the 4 domains that I still have access to I can simply export everything with a plugin and I can do it that way.  For the domain I don't have that option because I updated DNS I'm manually copying everything over but when I do I can't access wp-admin I get Error establishing a database connection

you need to check wp-config.php for db connections and also check your DB & and DB user

Thanks didn't look here but I figured it out and got everything up and working besides email....  I keep getting a denial when attempting to send email from any of my 4 domains in roundcube.  Also if I do smtp test via command line....  Any idea what would be causing that?