I just did this recently, and I am not too techhie, but I can tell you what I did.
I registered my domain name with a 3rd party hosting company (There are some recommended hosting companies listed on www.remarpro.com) Then install the latest WP on your new server/host. Export your WP.COM files and import that file to your WP.ORG site.
There you go! It is super easy.