I saw this post, I'm not qualified to try to answer it, but I will say this.
If you learn how to wrap a web site/app in a docker container, and connect that site to an external database / fileshare, you have the core kernel needed to have easy access to the cloud services.
The cloud services offer various vendor-specific features. But unless you want to become an AWS engineer, etc., you will want to use each cloud platform's flavor of virtual machines.
Azure and AWS are fine to learn. I'm nervous that GCP will either be killed as a product, or your google account will be smoked by some AI, and either way, you won't be able to recover that investment in a google-controlled product.
I had someone who was an old Perl cowboy teach me Azure, but I'm certain that Udemy has a course that will work for teaching Azure or AWS.
Hope this helps.