How can I rearrange my website products from newest to oldest?

Store Design
1

How do I change the order of my product on my website? I dont want it to list by Abc, I want newest to oldest

2

This is controlled in the collection admin for collections pages on the online-store channel.

https://help.shopify.com/en/manual/products/collections/collection-layout#change-the-sort-order-for-the-products-in-a-collection

If this is a section in a theme double check the section for a sort setting, or the general theme settings.

Beyond that probably requires a theme customization.