Create a new folder in your theme folder. I would only use lower case letters and dashes (-) in your theme name. Inside your new theme folder, copy the header text in your parent theme style.css file. To declare a parent theme, you will need to declare a Template. You will also need to change your Theme Name, Theme URI, Author, Author URI, and Text Domain. Here is an example below using the Meadowbrook theme as my parent theme.

/*
Theme Name: Angie Makes Child Theme
Theme URI: http://angiemakes.com
Description: Child Theme for Angie Makes
Author: Angie Makes
Author URI: http://angiemakes.com
Template: meadowbrook-premium
Version: 1.0
Text Domain: angiemakes-child
*/


/* =Theme customization starts here
-------------------------------------------------------------- */

By default, WordPress will not load the parent style.css file. So you will need to add the following code to your functions.php.

function angiemakes_child_enqueue_parent_theme_style() {
	wp_enqueue_style( 'parent-style', get_template_directory_uri().'/style.css' );
}
add_action( 'wp_enqueue_scripts', 'angiemakes_child_enqueue_parent_theme_style' );

You can read more about child theme development.