If default WooCommerce pages weren’t created for some reasons go to WooCommerce -> Status -> Tools and use the page installer tool:
2. If you set up new pages yourself, or want to change what pages are used for things like cart and checkout, you need to tell WooCommerce which pages to use.
To tell WooCommerce what pages to use for Cart and Checkout go to WooCommerce > Settings > Checkout.
3. Here is the list of recommended plugins you can use with WooCommerce and this theme:
payment gateways: PayPal is set up by default with WooCommerce installation, other solutions you can find HERE
Google Analytics: Google Analytics Dashboard for WP
Facebook Pixel: Pixel Caffeine
SEO: Yoast SEO