Ok, great!
So the next thing you'll have to do is update your nameservers. Nameservers are part of the instructions for the domain that tell it where to direct to. You want it to direct to your WordPress.com blog, so you have to tell the nameservers to point here.
You'll log into your registrar (where you registered the domain), and find where you can manage your domain. There you will find an option to see and edit the nameservers. Right now, your nameservers are:
ns2.hostpapa.com, ns1.hostpapa.com
You need to change them so that they are:
NS1.WORDPRESS.COM, NS2.WORDPRESS.COM, and NS3.WORDPRESS.COM
Once you do that, it will take a little while (usually a few hours) to propagate across the web.
Then you should be all set!
Let me know if you have additional questions!