i am trying to create an override for category blog, but i cannot fund blog.xml in the back-end. Can you advise how i can find it.

Thanks

blog.xml?? I think youre wrong!

Layout overrides
This way you can also override system files. For example, just take the Joomla article layout /warp/systems/joomla/layouts/com_content/article/default.php and copy it to your style folder /styles/STYLE-NAME/layouts/com_content/article/default.php and modify it. Now your modified article layout file will be used instead of the default system layout