Wait, are you referring to Field of Glory 2, or Field of Glory: Empires? As far as Field of Glory: Empires is concerned, it would be logical to find the whole UI to be more than just a little confusing. However, if you had already played turn-based games such as Civilization IV for example, the whole mechanics are more or less similar. Similar in the sense that the mechanisms that these two games provide to the players are actually quite intuitive.
In terms of an empire's nation building, the game provides you with different choices of buildings to construct, each one belonging to a different category (there are four); Food&Health, Infrastructure&Equipment, Money, and Culture. Next, once you've finished constructing a building, that building will now provide you with a flow of supply in regards to the building category from which you chose that particular building. Not only that, what makes this quite similar to Civilization IV is the fact that you can boost the production of those supplies (be it food&health, infrastructure&equipment, money, or culture) by moving some of your citizens or slaves to work within the building or supply categories you want your population to work in so as to boost the production taking place inside that category.
Tips: Try to build as many buildings that would allow you to produce enough food and infrastructure at a sufficient rate so that you could allocate your population to deal with the production of your empire's money and culture.
The trading in the game is done automatically, which should lessen the burden of having to micromanage your empire's operations. Just make sure that, like in real life, your empire's exports are higher than its imports, or you won't be generating revenue. You do this by creating buildings that allow the regions within your empire to produce certain resources that the other empires may not have. You'll also have to make sure to have the right buildings which can produce the types of resources that the other regions in your empire currently need, so that they won't have to engage in import with the other empires. Why? The benefit that you gain from importing resources from other regions within your empire allow for a cost reduction benefit by half the price. Where you would normally pay for 4 money for a particular resource from another empire, by importing the same resource from one of your regions, you'd have to pay only half that price (which is 2).
I hope you could find these information (although I'm definitely already too late). :)
Post edited May 23, 2020 by Preva