You may want to change the font that represents the text in either the title header or your site text. This is something that is easy to do.
When you get to the header, for example, all you have to do is click the "Edit" button at the top and you will get the directions along those lines. The font drop down box will appear and will load all the fonts in. Just scroll down the list and choose the font you are looking for. If you not looking for anything specific, well, just experiment and preview what your text will look like! if you want to change the size of the font you can do it here too.
As you get into the Content Editor or the various elements, it is possible to change the font here too. just click inside the box and you will see all the tools in front of you. You'll be looking for the bold capital "A," and if you scroll over it you'll see that it says "Font Name." Access that drop down box and make your selection.