Help to remove the default sidebar function and to know the min-width of menus

Hello.

I was trying to remove the sidebar function on my website, however, I am not able to understand how I can do this.

The function I need to remove:

add_action( 'widgets_init', 'twentytwenty_sidebar_registration' );

Furthermore, I have no idea where I should check to know the min-width of three kinds of menus in Twenty Twenty in the header. I am refering to the mobile, tablet and desktop menus:

https://drive.google.com/file/d/1It6R2_vvOzPNTTIyQFmBnxdndKVpz0_p/view?usp=sharing

Do you have a moment?

Thanks for your time

The page I need help with: [log in to see the link]