If you skipped the Setup Wizard or want to install missing WooCommerce pages, go to WooCommerce > Status > Tools and use the page installer tool.
To tell WooCommerce what pages to use for Cart, Checkout, My Account, and Terms and Conditions, go to WooCommerce > Settings > Advanced.
To tell WooCommerce what pages to use for the Shop page go to WooCommerce > Settings > Products.
For more detailed informations, visit the WooCommerce documentation