Ahaz was a king of Judah a really long time ago. He was in charge of a people called the Jews who lived in a place called Judah. Ahaz was not a good king because he did not follow God's rules and did things that made God unhappy.
One important thing that happened during Ahaz's time was that he was attacked by the king of another country called Aram. Ahaz was scared of this king and asked another king called Assyria for help.
The Assyrian king helped Ahaz, but it came at a price. Ahaz had to pay the Assyrian king with lots of money and valuable things from the Jewish temple. This made God even more disappointed with Ahaz because he was supposed to protect these holy things.
Overall, Ahaz made some not-so-good choices as a king and did things that made God unhappy. But, there's always a chance to learn from our mistakes and do better next time!