Wrong path.
To create new your own blog layout with your unique name, you should use Joomla standart override system and read Joomla documentation about override Category Blog. There are nuances - in addition you must create your own type of menu item and make changes to XML.
To override default blog layout that comes from from Helix (Finion) template, you must copy all files,
from
/plugins/system/helixultimate/overrides/com_content/category/
to
/templates/finion/overrides/com_content/category/
as they are interconnected.
From my experience. In 90% of cases, overrides are not required. Only CSS is enough. Describe what you want to achieve with blog layout.