Hello @prince,
We would like to apologize for the trouble.
Actually, the widget that you are referring to is EM: Featured product Carousel. This widget will only be seen in the widget section after activating the WooCommerce plugin.
So please activate the WooCommerce plugin and then add the above-mentioned widget.
Also, as for the demo, we will work on it and release the update adding the feature for importing the demo content.
Thank you.
Regards!!