You can add pages to the site from Site > Pages in StoreHippo admin panel. Edit the content in the static page if required or add a new static page.
https://help.storehippo.com/topic/pages
To add navigation go to Site > Navigation in StoreHippo admin panel. Edit the relevant section, in the Title mention "Page Name" and in URL mention "/page/alias of page"
https://help.storehippo.com/topic/navigation