Download and Install it! Then, open the icon on you desktop you can see this
My screen shoot on VMwave. You need to create a new system at next step.
ubuntu16.04
The next step is to download an iso file of OS which you want. Here I share my experience on setting up the ubuntu 16.04. If this is the first time you are using the virtual machine, you can just follow steps as below.
Download ubuntu 16.04 iso file. Here is the download link.
Install ubuntu 16.04 on your VirtualBox
Create a New Machine
Create a new machine.
Provide memory for virtual machine.
The storage limit for you virtual machine.
You have already create a new virtual machine on VirtualBox.
Import the iso file(start the new machine)
Import the iso file which you download at second step.
Setup the machine
install ubuntu
You need to connect the internet if you select any option here.
Install the Virtual Device
VirtualBox
ubuntu16.04