Like I said, Te'reyak isn't the most successful hunter. But his connection to his ikran is very strong. The fact is that Te'reyak didn't purposely go through a rite of passage to get his personal ikran. It was a fairly ordinary day for a young navi just strolling through the woods. It didn't look like anything was going to go wrong until he met an injured ikran.
The young navi knew that these creatures are dangerous, especially when they sense their future owner. But something jerked in the boy's heart, perhaps a great pity for the suffering animal. As it turned out, the ikran had chosen him, so it wanted to attack immediately. However, Zaote was very weak, so in the usual sense it couldn't do anything. Which allowed the young Tereyak to help treat its wounds. He helped Zaote set up a safe nest, as far as was at all possible for a young navi. And for some time he kept coming back to Zaote to take care of it and heal wounds. Eventually the ikran itself allowed him to establish their bond. Tereyak's older sister witnessed this. Although one might consider such an incident unusual and essentially a blessing from Eywa, he was still told off for being reckless. That he didn't tell anyone about it.