In administration panel go to Configuration => Configure modules
Select Taxes module
Tax rate will be selected as default when adding a new product or a shipping method.
Check out products documentation.
Check out shipping methods documentation.
Special tax rate, which is set automatically for all countries outside the EU.
In order to display the tax rate ex, both delivery country and country in the billing data must be outside the EU.
In administration panel go to Configuration => Configure modules => Invoices.
Check out invoices documentation.