How to create categories and associate them with posts

Thanks a lot, you've been helpful. Unfortunately, however, you show me all the categories and their relative counts. I would like to show every single category, I'll explain it better.

If you go to miosito.com/category/love

I show counting articles and articles

Thank you anyway, you have been kind

PS: Okay, okay, I did this

PHP Code:

public function category($slug_category) {

        $data['cpcs'] = $this->post_model->count_per_category();
        $data['count'] = $this->post_model->countPostCat($slug_category);
        
        $this->load->view('post/category', $data); 
    }