And I'm no guru it seems the style is to be applied to an object by name but you have class but no object.
Also, put your web page through the usual CSS and HTML checker tools.
<p class = "Coolkids">Hello guys</p>
<p class = "Coolkids">Paganis' are fast and lightweight</p>
<p class = "Coolkids">Paganis' are exotic cars, and are actually <br>very expensive.</p>
-Please explain to me why this isn't working.