Yes, you can pull information from an existing website and create a new site with Impress.ly.
To transfer contents from existing website to Impress.ly:
- Go to your impress.ly account at https://my.impress.ly/home
- Click on 'Create new site'.
- Click on 'I don't have a Facebook page' or '>' button
- Enter your website URL and click on 'Scan'
- Select required options, theme and create your new Impress.ly site.