Creating dropcaps (a highlighted first letter of your content) is quite easy. I just requires that you have installed the StagTools plugin. Once you do so, select the letter you want to edit, click on the shortcode generator icon (as shown below) and select Dropcap.
For the demo, the Dropcap shortcode looks like this:
[stag_dropcap font_size="150px" style="normal"]A[/stag_dropcap]
This means that we have set the value of font-size to 150px, and the style to Normal. Feel free to experiment with different values on your own.