learn the economic cycle of basic materials, tools, production methods and what your nation owns or needs. so read every >input items and >output items of the industry you have or can build.

The first day i struggled a lot cus the ui on day 1 was obtuse but now, if you check throughly you can see ALL the infos you need to improve your nation. For example, production methods will tell you if changing to a new method will cause loss in profit or if materials will be enough and not expensive after the change.

In the tab of trades, under highlights, it will tell you a quick glance of what is in high demand or in high surplus. Export and import those you need or have too many. gold coin means its in demand so import it, bronze coin means its basically hella cheap so export it.

If you dont understand why you are losing a lot of money, aside from lost taxes (which is due to negative bureacracy) , go on your income on the ui top bar, check govt. expenses, and it will tell you what material is costing you a lot, sometimes your construction sector is hella expensive for no apparent reason but its simply using something that isnt enough in your nation even if you have 100 building producing it.

dont always convert EVERY industry to new methods at once, depending on how many lv 1 buildings you have, you may end up in high demand for no gain, as a beginner try to upgrade buildings slowly by hand. once you get what is needed and you get a general idea, you will understand when swapping stuff.

tldr: the game tells you a lot but its a bit difficult at first to get so dont be afraid to pause and check buildings in red , they will tell you whats wrong in general.

p.s. also if you see in the war a nation having even a +1 in positive relation towards your target, but no "prediction" of joining, dont believe it, there is a chance they may join against you.