On Ubuntu/Debian, VirtualBox is installed with the following command:
sudo apt-get update
sudo apt-get install dkms virtualbox
You can view the version of installed VirtualBox using the command:
vboxwebsrv -V
You can start through the menu or by executing the command in the terminal:
virtualbox
You can start the virtual machine with the command (where ixnfo is the name of the virtual machine):
VirtualBoxVM --startvm "ixnfo"
See also my article:
Installing phpVirtualBox on Ubuntu