CentOS or Ubuntu difference will be negligible, but if the novice to learn hadoop recommended for Ubuntu Hardy
First install VirtualBox
https://my.vmware.com/cn/web/vmware/info/slug/desktop_end_user_computing/vmware_workstation_pro/15_0
Then download the ubuntu
After installing a new virtual machine
Finally, click on ,, to continue until the completion of the installation do not skip