[Theme Horse Support Team]

Hi ilayxz,

Create the same structure in the Child theme will not overwrite the parent theme. View below example link that we have already defined how to edit page 404.php
Link Here

Also you can find some tutorial link here about Unhook themetic fuctions
link 1 and link 2

Also if you are unable to customize the code according to your need then you need to hire a developer. Sorry for this.

Thank you!