Yes that’s what the code you use will do as already mentioned it will style the ‘p’ elements that are the first child in each section.
You don’t actually say what you wanted to happen?
Did you only want to style a single specific element or a simngle specific element within a unique context?
Your question doesn’t actually describe what you want to achieve 
(Not to mention that in your page you are actually using first-of-type and not first-child anyway ;)).
I also notice that you did not add my fix from a previous thread and as a result your page feels very laggy when resizing the window.