Custom post types in 2014 theme – where is WP_Query?

I have difficulties to understand the new Twenty-Fourteen theme. Since I am creating a child theme, I need to understand how it works.

First of all, where is the call to WP_Query in that theme? I wanted to create a custom post type, but I cannot find anymore the traditional query that is used in loop.

I have two sections in my site, one for posts of type A and one for posts of type B. If I register both types and I add them to query by

$query->set( ‘post_type’, array( ‘post’, ‘page’, ‘A’, ‘B’ ) );

I suspect that 2014 Theme will query ALL posts every time. Is there a way to say to theme to query ONLY A or ONLY B?