enfold > Child theme question

Hi guys,

Quick question, because I am rather new to child theme setups.

I have made changes to config-templatebuilder > avia-shortcodes > masonry_entries.php

AND

header.php

I copied the entire header.php file as well as created a directory called config-templatebuilder, and within, a directory avia-shortcodes and placed a copy of the masonry_entries.php file.

Is this correct?

Should I copy the contents of the entire file or just add my changes in that file within the child theme? Reason I ask is because of future theme updates.

Direction much appreciated.

David