The first advice
The story of Yusuf opens with Ya'qub as a father giving sensible, practical advice. Yusuf tells him a dream, and Ya'qub's immediate response is: O my son, do not relate your vision to your brothers, or they will contrive against you a plan (12:5).
He knew his own family. That is worth telling a child, because it is not a dramatic moment — it is a parent noticing something and giving quiet, specific advice. The rest of the story happens because the advice could not prevent everything.
Beautiful patience
When the brothers came back with a shirt and a story, Ya'qub did not believe them. He said: Rather, your souls have enticed you to something, so patience is most fitting (12:18). The Arabic phrase is sabrun jamil — beautiful patience.
Years later, when a second son was kept in Egypt, he said the same thing again (12:83). The Quran gives him the same words twice, at a distance of years, and that repetition is doing something: this was not a mood he happened to be in. It was how he answered both times.
It is important to say what this patience was not. He wept until his eyes turned white from grief (12:84). His family told him he would destroy himself with it. He was not calm and he was not pretending. Beautiful patience, in the Quran's own example of it, includes crying for years.
Complaining to the right one
When his family pressed him, his answer was: I only complain of my suffering and my grief to Allah, and I know from Allah that which you do not know (12:86).
That single verse is the most useful thing in his story for a child. He did not say his grief was wrong or that he did not feel it. He said where he took it.
And then the last thing he tells his sons before the ending: O my sons, go and find out about Yusuf and his brother and despair not of relief from Allah. Indeed, no one despairs of relief from Allah except the disbelieving people (12:87). He had been waiting years by then, with no reason to expect anything.