Is it possible to install word press on the same server as my site?
For example my site is mysite.com, and my word press location could be blog.mysite.com?
Please let me know how I can have a blog with CS Cart.
You can absolutely have one with your cs-cart site. If you have a cPanel with your hosting account you can add a subdomain name 'blog' and upload wordpress in that folder using an ftp program.