Your hosting provider should be able to install Linux for you and provide the login and root (superuser) details.
Installing Odoo can be complicated. There are lots of steps to complete. It took me many weeks to figure out how to get Odoo installed and running on Linux.
My recommendation would be to ask your hosting provider to install CentOS 7 (the latest version of CentOS linux) then follow this tutorial:
http://odootricks.wordpress.com/2014/09/18/installing-odoo-8-on-centos-7-with-virtual-python-install/
I found it easier to install Odoo on the newer CentOS Linux 7 as it already includes the correct version of Python. Alternatively you can install on Ubuntu using some of the links suggested above, but I personally found more success with CentOS. You mileage may vary.
Either way, good luck!
u can refer to this link http://www.theopensourcerer.com/2012/12/how-to-install-openerp-7-0-on-ubuntu-12-04-lts/
sorry then ^_^ just try to help