Changing Widget Font

If you just want to change the title, then just use the code below and add your own CSS

.footer-widgets h4 {
  *styles go here*
}

Or did you want to change something to do with the content in the footer? If so, then use the code below and again, add you own style:

.widget-area {
  *styles go here*
}

Ok, just use the top bit then, I am presuming you know how to add the custom CSS to your theme if you have played around with it previously.

By my *styles go here* element, I mean adding your own styling. So if you want to make the text bold, for example and increase the size and underline it. The custom css would be:

.footer-widgets h4 {
  font-weight: bold;
  font-size: 30px;
  text-decoration: underline;
}