Read More button not going anywhere new

In Minamaze, I’m trying to figure out how to organize my posts so any about coupons can be found when you click on the coupon category’s ‘Read More’ button. But even though I’ve selected the ‘coupon’ category when creating a post, it is only showing up on the main ‘blog’ page. When I click on any of the ‘Read More’ buttons, I’m brought back to the main page.

This is probably a very basic question, but I cannot figure it out.