Importing existing sites into Pagestead is not possible. You could however add your own custom blocks to Pagestead to match the site/page you’re looking to import.
FAQ: Can I use a WHM/cPanel server to host Pagestead?
FAQ: What server / VPS and hosting company do you recommend we use to run Pagestead?
FAQ: How can I force Pagestead to use https/ssl?
FAQ: Why are my page and template thumbnails not being generated?
FAQ: Can we add additional public pages to Pagestead, like a custom home page?
FAQ: Site and template thumbnails are not getting generated; why is that?