virtualbox.org

Sorry in advance but I'm a complete noob in regards to virtualbox.
I've installed VB and installed a guest OS (Oracle Linux) and tried to install some packages with yum but it seems that it doesn't work:
[root@db01 ssh]# yum install xorg-x11-apps
Loaded plugins: security
Setting up Install Process
No package xorg-x11-apps available.
Error: Nothing to do

If I try something else like;
wget virtualbox website it works as intended.

So is there any way I can test that I actually have connection oracle repository?
Is there any special things I need to do in virtualbox to get yum started?
Thanks guys

yum update should help to let you know. It all depends on whether or not you have enabled the public repo in OL

By the way yum is a package management feature of the OS and has nothing at all to do with VirtualBox