Most of the lighting nodes we provide are built specifically for our Custom Lighting model, meaning that they can't be used in other contexts. Also, the Standard Surface shader has its own lighting calculations, while the Unlit shader template has none.
Ideally, you should use the Custom Lighting model to create unique node-based lighting for your Surface shader, but you may also use the Unlit template as a base to
build your own custom template in order to suit a specific pipeline or purpose, although you'll need some shader knowledge in order to edit or create templates.
If you could further elaborate on what type of shader / effect you're trying to build, we might be able to provide additional insight.