Hello,
1) I can’t log in to your site https://prnt.sc/LhigcZ2HIDs-
2) I’m not sure what exactly you want to remove. Do you want to remove pages, posts, products that were imported during Сlassic demo installation? If you want to get the classic version of the single product template then go to Theme Options > WooCommerce > Single product builder > disable single product builder and save changes. After that go to Theme Options > WooCommerce > Single product and choose the template with the 50%image + 50%content.
Regards