I can’t seem to find all of the values that I need to set in order to define my default site layout. Is creating a layout element the “normal” way to set up the default layout? For example, I can’t find where I define “No Sidebars” in the Customizer. Also, full width, etc. I did find that I could set up a layout element and define all of these but that seems like a roundabout way to do it.
I am using a “learning” site, not ready for production. I am moving from Astra.
For global styling changes you should use the Customizer.
Sidebars are set in Layout > Sidebars.
For dynamic changes to layout than you would use the Layout Element. E.g remove Sidebars on Posts in Category X.
However the Layout Element also includes the Page Builder layout ( full width / contained no padding / content width ) and the Disable Elements Module. So here you can set pages to full width, remove theme elements etc.
Further to this you have post editor Meta Boxes for Layout, Page Builder Container and Disable Elements.