Looking to access your theme's code or language options with Shopify's new theme editor layout?
In your Shopify admin click on Online store > Themes
Next to the theme that you want to edit click on the Menu button which is a small square with 3 blue dots
This will open a submenu of options which includes: Edit HTMl / CSS and Edit Language
These collection templates are:
Collection = 3 products per row
Collection.4-column = 4 products per row
Collection.sidebar = Sidebar + 3 products per row
To choose a collection template your theme will need to be published and live on your site.
In your admin click on Collections then choose a collection.
Look to the right of the page you will see: Template
Here you can choose which collection template to use from the dropdown menu.
Save your collection when done.