Hello,
We provide import of products examples with placeholders, so you need to upload own products and images. Please read WC documentation – https://docs.woocommerce.com/document/managing-products/
XML files of all demos you can find here https://www.8theme.com/downloads/ (XStore import files).
If you want to get products of certain demo version, let us know and I will generate the import file.
Regards