npm create @fluid-app/fluid-site page -- --template html starts one.
Load the SDK
Every published site serves the SDK at/_fluid/sdk/v1/sites.js. Import it in a module script:
index.html
fluid sites dev serves the SDK at the same path when your installed CLI includes it. Otherwise that path answers 503 and says how to update the CLI.
Pages
Put each page in the folder:/about is answered by about.html only if you add a route, or by about/index.html with no configuration. See Routes.
Deploy
fluid deploy sees a folder of HTML with no build and publishes it as it is.