This is an important point regarding backups which are critical in ‘Production’ environments. This is why one of the fundamental understandings of any sysadmin (be it press-ganged or professional it to create a reliable and robust backup environment, and then test it, before anything else. No-one builds a luxury home then installs the fire system and security months or years down the line).
It all about building blocks, start where you’re comfortable and build on it. If you get stuck, do your research and troubleshooting (no-one wants to help someone who can’t be bothered to help themselves), and if you are still stumped, come to the forums. That’s why they are here, to promote Virtualmin / Webmin (which is a fantastic panel) and Linux. The vast majority of people here want you to succeed with Virtualmin and are happy to help.
As for backup guides you quite right there are hundreds and you’ll need to detail what your current use case and budget for backup. A budget for backup in a production environment isn’t a trick question and if the answer is £0 / $0 then people really shouldn’t be running any type of servers in a production environment. You can get a great backup environment setup under AWS-S3 compatible systems for under £6 per month. But it all depends… how much data, how much ingress / egress. What is your retention requirement etc, etc?
Getting these things right requires time and effort. But it is less time consuming and stressful that trying to deal with a problem at the same time.
There is no way to put a racing saddle on a donkey and think it will win the Arc-de-triumph. You have to start with the right material from the start, then put in effort and money.
A good place to start with backup is using Virtualmins S3 (any S3 compatible should be fine, we use Wasabi.com) backup. They all come with great documentation, but you’ll need to also understand IAM, more reading.
Get yourself a cheap development enviroment to ‘play around’ try AWS for Lightsail or EC2 (you pay by the hour or second depending) but they give you 750 hours free to start with. Spin it up, play, create snapshot, delete instance. Next time, restore instance, carry on playing, create snapshot, delete instance ad-infinitum.
The another option is to simply pay a sysadmin to do what you need, they have invested an unbelievable number of hours at getting good at what they do, leaving you free to do what you do best. It’s why I pay an accountant! - he pays for himself in what he saves in time and money.
Possibly the best option if you’re in a production environment, is to go for a Virtualmin pro subscription starting at $6 per month (10 domains) it’s a bargin!! That’s with premium support: Buy Virtualmin Professional | Virtualmin
I really hope you’ll stick with linux and virtualmin and if you’re truly stuck we are all here to help each other… we all get stuck sometime and need a helping hand.