Pay attention to the basic networking part. Especially where it says that you can refer to a container by name in your configurations
Then have a look at Caddy, a web server, to use it as a reverse proxy. You will end up with very simple configurations Read about reverse proxy in caddy's excellent doc.
Test on a machine in your lan first, by installing docker on it and administrating it via ssh,b this will be how you will interact with your VPS.
Install the containers you are interested in and configure them.
When you decide to move them to your VPS, make sure to use long passwords (and MFA if available) sans expert only 80 and 443 ( both will be marked by caddy to he right way ootb). The containers for week known apps are usually secure by default, and they highlight in their docs what you ansolutely need to change.
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After some time, when you finally understand everything, you will reorganize everything. No worries, containers are made for that, your data is independent.
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Then you will realize that you actually need an OS that is almost empty except for docker and a backup program (easier to use it at the OS level than as a container). You should consider borg.
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Than you will move to home automation with Home Assistant