The first gate
When Atreyu seeks out the Southern Oracle, he has to pass through three gates. The first gate is a pair of yellow sphinxes that shoot lasers at anyone that tries to pass between them. The second gate is a magic mirror that reveals one's true nature. The final gate is the No-Key gate, which causes the person to lose their memory, and can only be opened then. And beyond them is the Southern Oracle....which looks exactly like the first gate except that it's blue.
How do you get through the gate?
You need courage and also you need to be a child. ( a boy if you talk about the brave warrior and you are Atreyu.) You need to have a kind and thoughtful heart. And that is how Atreyu got through the first gate. And was strong and was trying to save Fantasia. From the nothing (a big and strong wind that blew anyone away except the humans).