<div>
 <p>
  Once upon a time..
 </p>
 <p>
  A beautiful princess..
 </p>
</div>

div p:first-of-type:first-letter { font-weight: bold; }

<div>
<h1>My Great Title</h1>
<p>
In my younger years I was a great man, but all that changed when I saw...
</p>
<p>
I struck him for shaming my name, my family, my life. It was a shameful...
</p>
</div>

div p:first-of-type:first-letter{
/* add your awesome code here */
}

div p:first-letter

div p:first-letter{
 color:blue;
}

<div>
 <p class="FirstLetter">
  Once upon a time..
 </p>
 <p>
  A beautiful princess..
 </p>
</div>

.FirstLetter:first-letter {
   // styling rules here
}