If you are not technically inclined and have nobody that could handle the WP move for you, then your route makes sense since you are only 18 posts in.
As for moving WP, there are actually only 2 parts to it. The website files (aka your root directory) and the database. Once those have been moved, everything else (plugins, settings, etc.) will fall into place.
After that, the only thing left are the redirects from blog.mydomain.com to mydomain.com, which is accomplished with a rule in .htaccess file.
