I removed the Store Name from the end of the title tags by removing the following line in the theme.liquid file. (Assuming you haven’t made any changes to the file yet, this should be found on Line 23)
{%- unless page_title contains shop.name %} – {{ shop.name }}{% endunless -%}
I am not sure you would want to remove the entire title, would you? I believe that will negatively impact your SEO.