You can use the LayerStateManager command to save and import layers, or simply import the .3dm file and all layers will be imported as well. And since your import objects are automatically selected on import, just press delete and you’ll be left with just the layers.
I don’t think Mac Rhino has layouts yet, it didn’t when I was trialling it for a year or so but it’s really helpful using templates. Set your standard template which you use as the default and it will always open with that.
Behind my Layout screen is how the template files look on Rhino for Mac. Not everyone on the Rhino for Mac category has used Rhino for Windows, so showing Windows images may be a bit confusing. FWIW