Hello,

That is fine. Actually, even if you set the sidebar, it should not break the page.

Do not delete the child theme, perhaps you have custom PHP there, you may need it later, let it be.

Have you solved the issue with Woocommerce mail? I am not sure Woocommerce has the option to send mail on the new order. In any case, test the sending email on contact form 7.

If you have any questions please feel free to contact us.

Best Regards