In your first post:
Are you sure it is also able to connect to internet, if it can not establish a connection, it will only be able to install a very minimal system ?Using USB Drive with bootable ISO: Debian 9.4.0 AMD64 NetInst
It sounds like it has connected, and is going ok, obviously though , the speed will depend a lot on how good your internet connection is, for me , mine is very poor, and slow, installing a full version of Debian, with DE, is essentially impossible. To download a full version, with DE, and make a CD or DVD can take up to 12 hours or more, for me, ... but any way that is another topic.
Also, some where , you mentioned about using Debian, with the CinnamonDE,
is that what you are trying to install ?
A DE of any kind, would slow down the install considerably, they are all rather bloated, === looks like I am going to drift into another topi , sorry, but anyway,
that leads to one more question, Why, or what is the purpose for setting up the
Virtual Disk or disks, ? Are you planning to setup a webserver,,and hosting, or what ?
I know, your reasons really don't matter, but on the other hand there is some things I would like to suggest, but I need to know more about what you plan to do with this, I mean it is much more then just a Desktop PC, it is intended as a server, etc,... if it is just experimenting , to learn, then I have several suggestions, if it is intended to be a on-line server, then I also have some suggestions, but I need to know more about what your intentions , plans are for this machine.
I still have not had breakfast, just finished chores, etc,... will be back later.
P.S,
I took a quick look at the guide, and it seems ok,... any way I need to get some food in me, or I really will start rambling, it is hard to concentrate and stay on topic when one is hungry.>then I booted into the installer, and followed THIS GUIDE.
In a nut shell, I was thinking to suggest trying to setup another VD , and install something simple, small to it, Debian can be rather difficult even on a real HD,
but for now ,we will have to just see how this goes, since it appears to be installing, ...