Did you used cordova plugin add plugin.name, ex: cordova plugin add cordova-plugin-geolocation?
After that step most of the plugins will have their own instructions for use, ex for the former geolocation plugin:
navigator.geolocation.getCurrentPosition(onSuccess, onError);
After installing most of them should be available either in window.plugins or navigator variables.
SideNote: In ionic 1 there was ngCordova but idk if it can be used in ionic 2, most likely not.
SideNote2: Check this link to another forum about ngCordova, will clear a few questions: Ionic 2 with ng-cordova