This tutorial explains how to add image block shopify theme and make the blocks editable from the backend. Here it create a section in the backend where you upload the image and linked that to the collection.
This tutorial explains how to add content block homepage shopify. Here it explains how to create editable content blocks.
This tutorial explains how to export import blogs shopify API. Using Shopify API data can be export from one store and import to another programmatically.
Please refer other PHP tutorials