When I run qterminal in xterm and with root privileges ( su qterminal ) I can see the prompt for qterminal .
If I only run qterminal ( in xterm ) I only see a black terminal with no prompt.
That is because toot has a shell set already, /bin/sh
If you are not comfortable editing system files, if you install Konsole, you can specify a startup command in its settings. Just use /bin/bash as your startup command and then use it.
Even if you don't do that, Konsole will still run /bin/sh for you on its own.