You will create your survey pages in NationBuilder, just as you normally would, though you will add a lot of additional features/functionality in FormJoy. To create a new survey page:
In your website's backend, click "New page".
Give your new page a name and slug, click "Show all page types" and select "Survey" from the list of options
Navigate to your new page's Survey Settings > Basic. Under 'Survey', either connect this page to an existing NationBuilder survey, or click the "Create a new survey" button to connect a brand new survey.
Open your new survey page in your web browser, and you'll see your one-page FormJoy survey already displaying!