GENUINELY how do I do economy in this game (I haven't played since release)

I bought EU5 when it came out and it was the only game I played for a solid month, but I haven't really played since. I thought I did alright, but then I saw what people online were doing and I was like 'how are they so good?' or maybe I was just bad lol. anyways I quickly realised that my economy simply wasn't as good as other people's and now that I want to get back into EU5 I just wanna know how to do better. Ive seen that some of the updates have changed things but idrk I haven't played basically since release.

anyone got any advice on how to do well with economy?