Hi,
There is actually no setting to turn off the display of taxes in the checkout or the order / invoice /emails
There are settings for the unit price, total price for a product row, and for the sub total to be with or without taxes, but there is no setting to display or not the taxes row between the sub total and the grand total, and that's the same for the grand total which always includes the taxes.
So if you don't see the taxes row between the sub total and the grand total on the checkout/cart/order/invoice/emails, it means that either you didn't configure any tax rules in the menu System>Taxes, or that you configured one or several but that none of them are deemed applicable for the current cart / user address.
So first thing would be to provide a screenshot of what you have in System>Taxes so that we can better understand your situation.