how to override parent functions.php in child functions.php - php

Question

I am looking for some suggestions on how to override or replace some functions that are loading in a parent theme and move them into the child theme so we can make alterations to the files themselves in the child theme.
We have duplicated the structure and files of the parent theme into the child theme, but can't yet find a way to prevent the parent theme from loading and load the child theme files instead.
Essentially it's all the require files listed below that we will duplicate and alter in the child theme, but need to find some way to override the parents functions.php.
We have tried multiple ways to do this but just can't seem to get it to work so far.
This is the current parent functions.php file:
/**
* moto functions and definitions
*
* #package moto
*/
if ( ! function_exists( 'moto_setup' ) ) :
/**
* Sets up theme defaults and registers support for various WordPress features.
*
* Note that this function is hooked into the after_setup_theme hook, which
* runs before the init hook. The init hook is too late for some features, such
* as indicating support for post thumbnails.
*/
function moto_setup() {
global $pagenow;
if ( is_admin() && 'themes.php' == $pagenow && isset( $_GET['activated'] ) ) {
wp_redirect(admin_url("options-general.php?page=moto-system-status")); // Your admin page URL
exit();
}
/* snip irrelevant code */
}
endif; // moto_setup
add_action( 'after_setup_theme', 'moto_setup' );
/* snip irrelevant code */
add_action( 'after_setup_theme', 'moto_content_width', 0 );
/**
* Register widget area.
*
* #link http://codex.wordpress.org/Function_Reference/register_sidebar
*/
function moto_widgets_init() {
/* snip irrelevant code */
}
add_action( 'widgets_init', 'moto_widgets_init' );
/**
* Implement the Custom Header feature.
*/
require get_template_directory() . '/function/custom-header.php';
/**
* Custom template tags for this theme.
*/
require get_template_directory() . '/function/template-tags.php';
/**
* Custom functions that act independently of the theme templates.
*/
require get_template_directory() . '/function/extras.php';
/**
* Customizer additions.
*/
require get_template_directory() . '/function/customizer.php';
/**
* Load Jetpack compatibility file.
*/
require get_template_directory() . '/function/jetpack.php';
require_once get_template_directory() . '/include/aq_resizer.php';
require_once get_template_directory() . '/include/moto-sys-req.php';
require_once get_template_directory() . '/include/moto-enqueue.php';
require_once get_template_directory() . '/include/moto-functions.php';
require_once get_template_directory() . '/include/theme_plugin/plugin-activate-config.php';
require_once get_template_directory() . '/include/wordpress-reset.php';
Any suggestions?
Thank you in advance.