It's not really about Wordpress itself but about the theme you are using.
Think of Wordpress as the skeleton of your website. It is there to provide the foundation and core functionality.
Your theme is where the responsive/mobile functionality comes from. Most premium themes are now designed for desktop, tables and mobile. Most will also come with a Theme Panel which will allow you to change settings and etc.
I would check ThemeForrest Wordpress section.
Lastly, when are choosing a theme, my strong suggestion is to look for a well established theme. Look for how often the theme is updated, how many support comments are on the page and how often the theme author is engaging with customers.