If you wish to have taxes applied to orders in your storefront, you can add them in the Taxes section of the storefront setup page. Simply add a description (such as “Sales Tax”) and a percentage (such as 7%).
By default, any tax you add will be applied to all products in a customer’s order. However, if you wish, you make a specific product non-taxable. To do this, scroll up to the Products section, find your product, and uncheck the taxable checkbox.