Modifying functions in a Customizr child theme

Help please… I made a child theme using Child Themify as described here: https://www.themesandco.com/snippet/creating-child-theme-customizr/

And what I’m trying to do is to remove the category, tags, etc. from appearing on my blog category and post pages as described here: https://www.themesandco.com/snippet/remove-categories-and-tags-buttons-in-the-post-metas-block/

I have 2 questions:

1. The instructions in the child theme post are unclear to me. Do I need to create and upload a new functions.php file? It says the best way to modify the Customizr child theme is by using hooks and classes, but I don’t know how to do that either. Should I just duplicate the functions.php file and add it into my child theme’s folder via FTP?

2. IF copying and uploading a functions.php file via FTP: Do I just copy and paste this code snippet and then make all changes, or would the snippet need to be modified/custom written for each change? The code snippet I am referring to is located on the child theme instruction page under the heading Pluggable and is this

if( ! function_exists(‘name_of_function’) ) {
function name_of_function( $params ) {
// do some stuff with the $params }
}

3. Does anyone know a code snippet to stop displaying the share buttons on the category pages? Those should show up only on each individual blog post, rather than after each post when someone is looking at the entire category.

My website sections I want to modify are all the category pages such as this: https://www.thenakedlifecoach.com/category/news