Ty decided the first thing he'd like to try was to use his power to change himself. As you can imagine a scrawny, teenage boy would feel, Ty felt pretty unsatisfied with his body and had always wanted to be different. Now he could change that, the idea of holding off on it any longer wasn't something he could bear.
What did stop him was wondering *how* to change himself, at least for now. It might be fun to regress back to a child, or even to before he was born to get born as someone else- on the other hand, he could always try ageing himself to adulthood. Or he could try changing sex... or turning into an animal, or something animal-like that didn't actually exist like an anthro or mythical creature or alien. Maybe it might be nice to change reality, make people like him more or change around the way the world worked a bit? Ty was just realising how endless the possibilities really were.
Eventually Ty came up with the wish he'd try first...