Jason's call to adventure is when he gets a vision from Hera when he was talking to Chiron. Hera tells Jason that he has to save her.
Jason's refusal to the call happens when he is at camp half blood and he finds put he’s a Demigod but he does not believe it. He still is really confused since he has no memories and he doesn’t know what to think.
Annabeth is Jason's supernatural aid because she is a guide for them because she is helping the three of them get the hang of things around camp.
The threshold is crossed when the storm spirits show their true form and they attack Jason, Leo, and Piper and the first threshold is crossed.
Chiron is Jason's Mentor/Helper because he helps on this quest and guides him to do what must be done on this quest. Chiron is the camp director in charge.
Jason's challenge is at Aeolus’s ice palace, battling the 3 Cyclopes, the evil saleslady in mall, Medea. Jason’s temptation is that he worries about he can't take care of his friends.