Theme options is a place that you can customize your theme such like: change the logo, colors, fonts, layout, and other aspects of the theme without needing to know how to code.
To access the theme options, go to Admin -> Appearance -> Theme options.
In the General tab, you can change site title, description, primary color, primary font or even enable/disable preloader.
In the Social links tab, you can add your social links to display on the site.
You can add whatever social links you want in here.
In the Ecommerce tab, you can customize product listing page, number of products per page, ...
To change to text in footer of cart sidebar, just change the text in Cart footer description field.