In order to access the virtual machine, select your machine's settings, pick network and use Bridged network. Also, don't forget to plugin the cable.
(Vague title in case I add more reminders.)
Installing Guest Additions
To install Guest Additions, do the following: Sudo apt-get install dkms sudo apt-get install build-essential Reboot the server by entering the command sudo reboot Login in to the server. Go to the Virtualbox Devices entry on the menu bar of the guest OS and select Install Guest Additions… , this will load the Guest Additions ISO CD image. Change directory to media cd /media Create a directory called cdrom, this will become our mount point sudo mkdir cdrom Mount the Guest Additions ISO to the mount point sudo mount /dev/cdrom /media/cdrom Now change to the cdrom directory cd /media/cdrom Display the directory contents i.e. the ISO image ls Depending on whether you are running a 32bit or 64bit OS, run the relevant installer. In this case 32bit so enter sudo ./VBoxLinuxAdditions-x86.run
Citation from mylinuxramblings.com