Need help from Pros

So I would like to get better at this game but I am still bad. On YT, things can get confusing or the videos are maybe outdated sometimes (and boring). On the Internet, the veryy little guides I find are mostly to basic or also outdated. So I thought maybe I can get some better help here. I know a good part of the very basics, but that won't be enough to survive. I will list the things I definitely need to improve in:

Having a plan: What to do when I start a new match what should I change so do also with the in-game time progressing. Which factories, units, doctrines.

Economy: Which economic laws do I need to use when and how, how do I get a stable economy

Trade: How do I trade with AI nations properly (not just selling 1 of the item to each), which nations are the best to trade with

Military: how do I defend pre-war and in-war, how do I attack (here, details like units and doctrines, basically looking at every detail would be very appreciated)

Politics: which leaders am I looking for, How do I utilize laws and policies properly, how do I gain stability and political power the fastest way, how do I fight corruption the most effective way After country destruction: how do I fix my country again, how do I regain any land, what are the important things to focus on

I would very very appreciate anyone helping with these things or giving other tips and tricks. Very much thank u!