NetBeans needs to know your team number in order to connect to the cRIO. When you select the NetBeans window you should see a menu bar at the top of the screen. On Mac OS X, the options menu is actually called "Preferences". You'll want to select NetBeans > Preferences instead of Tools > Options.
From there, select the Miscellaneous tab and then FRC Configuration. Enter your team number as shown in the screenshot below. Note the screenshot is on Windows, but it looks very similar on OS X.
