Choose your name and machine type for the "new'" VM. And hit next.
I created a VM with 3 GB (3000 MB) of memory (I have 16GB on the machine) which is fine for a simple reverse proxy only server. If you want full UI you may need more.
Choose to create a new VDI virtual disk now. Dynamically allocated. You can probably get away with even less than 100 gb if space is short. Making one now with 100gb disk and it looks like plenty.
Before we start the instance and install the OS, lets make a few tweaks...
The default network is to share the same IP address as your host machine and translate the traffic through your host machine. Since we are making a secure network interface device I want this new VM to show up as a completely separate machine. Right click on your new VM Icon and change the settings. Change the network type from NAT to Bridged Adapter. This means that your VM will look like a separate machine.
After making that change, start your VM. It will ask for a startup disk. This is like putting an installer CD into a machine. Select your ISO for whatever variant of Linux you downloaded. The little foler icon will let you browse for you iso file. Hmmm this UI looks a little different from the last time I did this. Maybe lets try and "Add" to mount our ISO... That seem like it. Start it.
This will go through the installer process. Sometimes when you click into a VM it kind of grabs your mouse and holds it. In the lower right of the VM window you will see a hint about Right Ctl... that will escape your mouse back to the host.
Linux doing its thing....