PenciDesign Supporter replied
Hi,
1. Unfortunately, you can't import a single demo page. You can install & use the Elementor plugin, create a new page, then search & insert a single template/block as the screenshot below:

2. The page you've sent is a portfolio page, please install the Penci Portfolio plugin by going to Appearance → Install Plugins, then read the document here: https://soledad.pencidesign.net/soledad-document/#portfolio to create a similar page.
Regards,
PenciDesign.