Either it didn’t teach you anything at all, or it taught you the most irrelevant parts of the game.
I adore those games, and while I think they’ve made great strides with CKIII and Vicky 3, I agree that the tutorials are severely lacking.
You gotta just start with an easy country. The CK2 community used to call Ireland “Tutorial Island” since it was low key and a good place to learn the mechanics, same with Spain in EU, or Belgium in Vicky.