On the top right corner of the hunter trainer's window, there is a tab to adjust the display setting. You can tick whether to show what skills are available, unavailable and even which skills you've already been given, I think. Check to see what setting that is on.
At level 2, your first NPC should have given you a quest to go talk to your class trainer. Did you receive that quest and see the trainer at that point? If you're at the right person, then my guess is to check the tab mentioned above because you should have access to new skills at levels 2, 4 and 6 by this stage.
(P.S: Yeah, those Black Widows are pretty sweet looking)
Edited, Oct 6th 2007 6:09pm by Smallsword