I think Annabeth was talking about graduating high school (she's just wearing the UNR tee shirt the same way any senior wears the stuff of the college she means to attend, I think). She talks about the same things Percy does -- that he needs to get through his standardized tests before he can get to college.
I don't even like the supporting cast of GoA. Blitz, sort of, and Sam is kind of interesting, but Hearth just annoys me with the angst, and Alex is pretty angsty, too. (I'm not fond of angst. Even Nico was starting to bug me by the end with everyone talking about how no one had ever known deep pain like his. What saved him was that he wasn't saying it, and seemed to stay focused on what he was doing. Plus, he had the brain to accept Will kicking him in the ass and telling him to get out of his little dark cloud.)