Functions.php in child theme

Quick question about adding code to functions.php in my child theme. When I created my child theme instead of doing @import, I added functions.php in FTP and put the following code in there.

<?php
function theme_enqueue_styles() {

$parent_style = ‘parent-style’;

wp_enqueue_style( $parent_style, get_template_directory_uri() . ‘/style.css’ );
wp_enqueue_style( ‘child-style’,
get_stylesheet_directory_uri() . ‘/style.css’,
array( $parent_style )
);
}
add_action( ‘wp_enqueue_scripts’, ‘theme_enqueue_styles’ );

Which from my understanding is the same thing as @import but is the better option now for speed of my website.

Now, I have tried adding new code below this in that functions.php in my child theme and it makes my site go blank. I understand functions.php is the one place where you can’t modify the same file that is in the parent. I’ve looked all over and haven’t found a clear answer. So Should I create a new functions.php file and name it something different on top of the original functions.php. So I would have TWO functions.php files, but one could be called for example functions-child.php. And then I would be able to add functions to it??? And would that be completely different from just adding code to the original functions.php. Because in the end I just want to modify the functions of the website, but I’m wondering if that second file would interfere with the first????

Thank You for any explanations