Page Attribute template not available

In my Woocommerce site I want to make my home page and shop page different but similar looking pages. I copied the theme homepage.php and put it into my child theme under the name “shoppage”.

I can choose a page template (including shoppage) for every page EXCEPT the shop page. For most pages, in the page attributes, there is a drop-down menu for choosing the page template. For the shop page, however, that drop-down template list does not exist. Instead there is a text box labelled “Order” which defaults to 0.

Can anyone enlighten me as to how to make the home and shop pages different and why my template doesn’t show up for the shop page?

Thanks!