@Jamesgarret answered how we can access the parameters of the plugin that are set by the administrator.
To answer your other question:
Also what is the data's name once it gets into the program? Does it
use the label that's set in the .xml manifest?
This is not the label - it is the name of the field you set in your plugin's xml. Label is the text that will be shown in the form left to your field.
It's also better if you could use some naming convention for the names you give to your fields. I have never seen anyone use words separated with spaces. It will still work though, but it doesn't look that good. Usually it's preferable to use underscores or camelCase convention, to separate words for the name of the field.
Finally, when you write a plugin, you should usually do it by extending the JPlugin class.
class plgSystemMyPlugin extends JPlugin
JPlugin Class is handling all of the basic properties for plugins, which will allow you to access them within your plugin's methods:
$this->params; //The parameters of the plugin as set in the admin:
$this->_name; //The name of the plugin
$this->_type; //The folder of the plugin.
$this->db; //The db object.
$this->app; //The application object.