I was a catechism teacher for a few years.
In my humble opinion…it’s supposed to do exactly what the word says…
It’s supposed to create an environment where you can be “confirmed” in what you’re about to do…to go before the bishop and declare before heaven, hell, purgatory and all of Gods people…that you choose God and to follow Him through the Catholic church. Not that you understand everything the church teaches, not to understand deep theological concepts…but to really be confirmed and lit on fire with a deep love for Jesus whom you’re promising to follow.
I have to say, I think MANY catechism classes have become weak and I’m sorry you’ve had a bad experience…
But it’s good to remember that the Catholic church is Jesus’s church and He is ultimately running the show and is able to deal with any searching soul who is sincere.
God bless
If you need any assistance with going farther, don’t hesitate to ask.