I want to monthly rent a VPS in the very near future to host a website, a Peertube instance and an email server as minimum. But despite having used Linux as a home operative system for 3 years, I pretty much known nothing to properly secure online services.

So I want to first have a “dummy” cloud system where I can mess around with configurations and everything without risking losing money while I am still learning.

While typing this it crossed my mind I could also create a virtual network in Virtualbox, at least when I used it on Windows years ago it allowed you to do it. Could this also work? To create two virtual machines under the same network with one acting as server and one as client?