Your store includes a collections list page at the URL your-store.com/collections that shows all of your collections in alphabetical order. This customization shows you how to specify which collections are included, and how to change their order on the page.
The current versions of all free Shopify themes include settings that allow you to make changes to the layout of your collections list page from the theme editor.
Steps:
From your Shopify admin, go to Online Store > Themes.
Find the theme that you want to edit, and then click Customize.
From the drop-down menu at the top of the page, or from the Templates menu on mobile, select Collections list.
Click Collection list page to view and change the settings.
Name your menu All collections. It's important that you don't change this name, because it's used by your theme to determine which collections to show on the collections list page, and in what order. The menu name doesn't show on your online store.
Click Add a menu item.
In the Add menu item window, enter the name of a collection that you want to show on the collections list page. Click the Link field and select Collections, and then click the name of the collection. To move a menu item to a new position, click and drag the dots on the left side of the menu item.
Click Save.
For some themes, such as Supply, creating the All collections menu is all that you need to do. To check whether any changes have taken place, go to your collections list page (your-store.com/collections) on your online store. If you see no changes, then you need to edit your theme code.
Customize your list-collections.liquid template
You can edit the code for your collections list page so that the page displays only the collections that you have included in the All collections menu.
Steps:
From your Shopify admin, go to Online Store > Themes.
Find the theme you want to edit, click the … button to open the actions menu, and then click Edit code.
In the Sections directory, click list-collections-template.liquid.