I have professional expereance with hosting PHP applications. I worked the last 5 years as admin at a small hosting company.
A good setup to host PHP in production is PHP-FPM. Have a linux user for every application and a FPM pool, so when one application is hacked, the data from the other is safe. (Keep software updated, so the chance to get hacked is drastically reduced!)
Using a unix socket might be slightly more performant than bind to local TCP port like 127.0.0.1:8000. It helps also to not reach the limit of open TCP connections for high traffic sites. But TCP is also OK, not much difference practically.
Here is the config of my NixOS VPS hosting some PHP applications: https://github.com/davidak/nixos-config/blob/13642818b0e6f3c9587b58627aa110f604b672a3/machines/atomic/configuration.nix#L141-L219
I use the Caddy webserver. It has good performance, automatic HTTPS using Let’s encrypt! and is very easy to configure. You might want to use Nginx for a common, high performance webserver or Apache, if you need support for site configuration using .htaccess file. Search for PHP-FPM config for the webserver you want to use.
phpMyAdmin is just a normal PHP application. It should be no problem to install and configure it using the provided documentation.
A simpler way to manage a database is Adminer. It’s just one PHP file you put in your webspace. That’s it. I used it a lot when i just want to do something quickly without proper setup of phpMyAdmin.
I hope that helps. Feel free to ask if anything is still unclear.