to show no tax at checkout

Hi,

You want to remove the display of the tax altogether ?
I would advise against that because in most of the countries (and thus probably yours too) it is required by law to display the taxes on the checkout of a website.
Nevertheless, you can hide it by adding such CSS code on your website:
.hikashop_cart_tax_value, .hikashop_cart_tax_title{ display:none;}