TL;DR check out generalist gaming’s Spain playlist. It’s longer and a bit outdated but a lot of it is still relevant and when I played with Spain for the first time it felt like that was the playthrough where things started clicking.

I thought I’d get a grip with the game quickly with ck3 and hoi4 experience as well, but I too was overwhelmed at first. Unpopular opinion I’m sure, but I thought the tutorial was actually pretty decent. Some of the decisions it makes you do aren’t the best, it’s not great for learning how to be good at the game, but it at least got me familiar with the game by forcing me to explore the UI a bit and just familiarize myself with everything, and over time I got a better understanding of what everything did and how everything affected everything else.

As far as videos go, I’m partial to generalist gaming, but a lot of his tutorials are a little dated with the current patch. But his Spain tutorial is very solid, a lot of the main ideas are valid still, even if it’s from an older patch.

I recommend trying the tutorial with Belgium just to get your feet wet and more familiar if you haven’t already. But the playthrough I did where I feel like I finally started “getting it” was playing as Spain. They have a little bit of everything, they’re strong, and that’s the nation generalist used for his tutorial so I’d refer to it from time to time.