Without admin login how can you export the product sheet from wooCommerce.
As Shopify only supports importing products by CSV files, you need to export your WooCommerce data into a CSV file format.
your product CSV cannot exceed 15MB. If you get an error when trying to upload a new CSV file, then check to make sure it doesn't exceed the size limit.
after that you have to import the sheet (CSV File) in shopify account.