Only a noob question because you asked it via a Known site! ;)
But it is a good one. Child themes only really need two files: the style.css and a functions.php. In the style.css file there's a block of text at the top with details about the theme. One of the lines has the name "Template" and its value is the case-sensitive name of the parent theme's folder in your /wp-content/themes folder. Thus to have your child theme pointing at the correct parent, you'll want to modify this "Template" line appropriately.
FYI: If it helps, Smashing Magazine has a pretty thorough article on WordPress Child Themes and what they're doing and how: https:/