Yes, that is correct, the regular ISO. I've always had an internet connection
so I do not know if an internet connection is "required" or just nice to have
during an install.
I used this text install full disk encryption method on a desktop machine and
on laptops without any problem. Can even change the filesystem used in the
LVM during the install, kind of buried in there, but it works.
It almost sounds as if his overall desktop installation wasn't completed if a
blank screen/terminal showed up instead of the usual GUI login screen?
Svamiji, during the install, near the end, where it asks which packages to
install, did you include a desktop package? If not, you'd just get a blank
terminal right after booting up. If you chose a desktop, you ought to get the
GUI login screen and a regular graphical desktop environment.
Since you got past the initial disk unlocking at boot, it wouldn't be the
full disk encryption that was wrong or bad.
Svamiji, perhaps you need to install a desktop? Maybe someone can provide the
command line for the standard trisquel desktop? I don't know it right off.