Welcome to Super! Now that you're ready to create a site, all you'll need is a Notion page.
Any Notion page can be turned into a site with Super. The page must be public. You can make a Notion page public by clicking the "Share" button in the top right corner of your Notion page, and turning "Share to web" on. After that you can click "Copy link" in the bottom right of the share popup to get your pages public link.
To create a site click the "New site" button in Super, enter a name for your site, and paste your Notion page URL. Your site should be live after a few seconds.
Some things to note about Super sites—all pages displayed on the site must be public in Notion and must be child pages of the site's home page. Super has this second restriction to prevent Notion pages you don't own from loading on your site, as well as pages in your workspace you may not want others to see.