Salesforce B2C Commerce enables you to run reports against captured analytics data. You can use the separate Reports and Dashboards portal, which graphs your site's sales, product, or promotion, technical, traffice and other data for a selected time period; or you can use the Business Manager Analytics module. Both capture and report on a variety of data from the B2C Commerce eCommerce storefront.
No matter which tool you use, for metrics to be meaningful, you should focus on the correlation between metrics and finite numbers such as revenue and number of orders. The overall goal of using metrics is to identify trends over time.