There are two areas to custom options for Shop page and Single product are Theme option and Custom setting for Shop which located in Theme option ==> Child Options such as Header, Footer, Layout, Page Title, Color, Typography
Any option is set to Default which is the current style of your Theme Option. So, if you want same settings on all pages, then you don't need to select anything. If you want a different option for Single Product page or Shop page, then you can choose any other option here as your wish.
You can view the area (1) in bellow image:
This is options in Page setting