So you are trying to use the online tools rather than the deskdop tools? I think you should be able to use the desktop tools in the 30 day period. There is no easy way to add additional styles in the online version, unless you have a local administrator, if I remember correctly.
From the KB article: http://endnote.com/kb/82614
The desktop version of EndNote and EndNote online are designed to share the same tools in Word. However, only one set of Cite While You Write commands can be active at any given time. You can toggle between the two sets of commands:
- In Word 2007/2010/2013/2016 , click on the EndNote tab and click Preferences.