You can modify the main body font to use the same google font you have set in any of the styling dropdown options since that font will have already been loaded in. If you want to load in a different google font, an easy option is to use a plugin (there are lots available for it).
For example, this would set the font for the Open Sans font:
font: 13px/1.65em Open Sans;
The Features page is created using a tab shortcode and large images. So you can use the shortcode editor to select the tabs and then edit the icons, insert it then edit the content of each tab.