Yesterday I came across the article with review of Jelastic cloud. The author explains this service in the following way: "It’s kind of like WHM/cPanel but hosted on a cloud and can also manage server clusters rather than just one server, and integrate many other cloud services (storage, CDN, DNS, etc)"
https://wpjohnny.com/jelastic-cloud-platform-review
Seems as a good suit for you to start with. They have control panel and automation of some infrastructure management processes, so you can get started even without profound technical cloud expertise and dive deeper eventually.
what about open-source Jitsi hosted on own servers? sounds like much more secure and controllable option. i used it just several times for group calls, so cannot say how full the functionality list is but so far rather good alternative to Zoom.
You can consider scalable packages offered by Jelastic, they provide standalone and clustered installations of WordPress (based on NGINX or LiteSpeed servers).
Standalone is much cheaper and totally suitable for medium size projects. The resources are scaled automatically and the price is based on actual consumption, so can be a good fit for you.
But of course it's better if you give more details about your requirements to understand what configuration will suit.