Did you mention to the team, or at least the leader, that you were new and needed some help? If you don't let people know you need a helping hand they're not gonna know to give it. I've found that if you let people know at least one person will help you along.
I've been playing this game since beta, and there are still a number of TF and task forces I've never done. Or it's been so long I don't remember. And I'll always tell the lead up front that I'm going to need a bit of direction.
If all else fails then I'd say to do less attacking and more watching. If the team move on, stop whatever you're doing and move with them. Like any other game it takes time to learn.