Hi @ezramod,
You can use the built-in product CSV importer and exporter under Products > Import.

Link to image: https://bit.ly/3cWQo5q
If you choose not to enable Update existing products
, any products in the import that match existing products will be skipped. The entire product will be ignored and you won’t get duplicates.
If you enable Update existing products
, then any changes you make to the product in the CSV file will then overwrite the product in the WooCommerce site. Products that don’t exist will be skipped.
If you want to have existing products updated and not skipping non-existing products you’d need to run the importer twice with the settings that you need.
I’d recommend having a new CSV file for new products, as those aren’t part of the WooCommerce store yet. When you’d like to update existing products, export a new version from the site so that you know that you have the latest information. Once the products are part of the WooCommerce store, they’ll be included in that export.
Thanks.