There are 2 types of templates that Magnolia supports if you want to use it to render content as well as supply it. There is a page template that is associated with over page and then there is a component template that is used to render components within the page. Each page can have only one page template associated with them while it can contain multiple components of different type and multiple instances of those components as well.
From what I can see, your first guide will only create structure for templates in the generated module, but not actual templates. And your second guide will only create templating function and component template to demonstrate that function, but not a page template.
So first, you should check that in your module structure, somewhere under /src/main/resources/<your module name>/templates
you have subfolder called pages
and in that folder you have defined page template. And second, you might want to follow this guide for creating and registering page template.
Or if you want to skip java module altogether and do it just as a light module you can follow the guide here.