This is the best tutorial how to create static "landing pages" on Hugo: https://discuss.gohugo.io/t/creating-static-content-that-uses-partials/265/19?u=royston
Basically, you create .md in /content/ with type: "page" in front matter, then create custom layout for it, for example layout: "simple-static" in front matter, then create the layout template in themes/<name>/layouts/page/, for example, simple-static.html. Then, use all partials as usual, and call content from original .md file using {{ .Content }}.
All my static (landing) pages are using this method.
By the way, I'm not using hugo new, I just clone .md file or copy a template into /content/ and open it using my iA Writer text editor. But I'm not using Hugo server either, adapted npm-build-boilerplate is running the server and builds.