But my issue is the coraline theme doesn't come with a plugins menu.
There is no FTP access to free hosted WordPress.COM blogs and we cannot install individual plugins or third party themes into them. Those found on the internet are for WordPress.ORG installs which run on different software.
http://en.support.wordpress.com/ftp-access/
http://en.support.wordpress.com/plugins/
If you wish to have complete control over a blog, the ability to upload themes and plugins, and to edit themes and templates then your option is to hire a web host and get a free software install from WordPress.ORG and self host it.
http://en.support.wordpress.com/com-vs-org/