To use virtual machines in the cloud may require that you have the bank account in existence as you'll be charged monthly for using the cloud VM services like Azure, Google Compute, etc. but it seems that Oracle has the integration feature of VirtualBox VMs to Oracle Cloud. Mostly, the cloud VM services may require that you fill in your personal particulars including the company name or some kind as if the consumption of electrical resources and data bandwidth is quite costly on both sides. There's no such thing as free plan for cloud VM service as if every plan is priced. There may be trial usage on Azure and Oracle Cloud when it comes to cloud VMs although it lasts for a month and that's it. I'm sure that cloud VM stuff is going to be quite handy for work use and to find a service just for personal use is not an easy find.
The next thing is the unattended guest OS installation similar to the 'Easy Install' feature found in commercialized version of VMWare Workstation. Normally, the setup interface poses a challenge when you install the OS yourself but the Easy Install-like feature makes things easier in which you have to fill in the stuffs yourself before starting the VM. Furthermore, certain pages of the setup wizards will be skipped but when it comes to Windows OOBE, there may be pages of the wizard that have the options of allowing things to be collected or some kind. I don't know if this new feature VirtualBox has will recognize this situation but that's how unattended OS install works and especially when you're test-deploying OSes to the virtual machines whether it's a personal, work or study stuff. Well, if you're studying the OS deployment stuff like I did, you can probably go for certified courses that have that practical topic as well. Be sure not to pick the wrong one of course. The last thing as of the Easy Install feature is the installation of the guest additions, something the deployment tools don't do by default as the guest addition stuff may count as an external desktop app you may want to add.
Needless to say, the Easy Install feature from VMWare Workstation is just for unattended installs so if you want to customize something prior to that, you may need some external deployment tools for it.
