Hi arimakidd
It is a K2 registration form setting, i added a custom css class to your Register menu item in your custom.css file .
Here below css i added
.register.componentheading {
font-size:39px;
font-family:'Open Sans';
line-height: 1.4em;
margin-bottom:20px;
font-weight:300;
}
This custom class is valid only for your Register menu item .
Regards