Hello and welcome aboard. I'll try to asnwer your questions:
Most likely you're playing the most recent expansion, Twilight of the Arnor (ToA), when playing GalCiv2 Ultimate via Steam. An easy way to tell is if there's a giant Terror Star in the background of the Main Menu. (Big structure with a rotating beamlike thingy around it.) It's also possible to start the original game or the older expansion (which is at least as good), but I don't know how that's been done through steam.
As for production: it's complicated! There are a fair few things that influence your production. Social and military production are not the same, but they are both production... yergh.
Let's take this from the top: There is a slider in one of the menus that lets you determine output: this slider applies to both production and research buildings and should always be set to 100% (it isn't when you start up a new game though, so fix this straight away!)
In the same menu, there are three sliders that let you prioritise research, social (planet building), or military production (ship building. These sliders combined make up 100%. What is important to note is that:
- you can only have one of those three at 100% if the other two are at 0%,
- research requires different buildings than social and military (which use the same).
To put it into perspective, lets take a non-existent planet that has a building on it that can produce 10 production and 10 research. Say you have put the sliders on 40 mil, 40 social, 20 research, what you'll actually get is:
(40% * 10 4 military production (which will work on ships), (40% * 10 4 social production (which will be used on buildings, if no buildings are being built on the planet, it will be added to shipproduction) and (20% * 10 2 researchpoints! If you then decide to build a researchbuilding that can produce an additional 5 researchpoints, your actual increase will be (5*20%) 1 researchpoint extra.
If you want general GalCiv2 information: https://www.galciv.wikia.com/wiki/Galactic_Civilizations_Wiki
A massively useful link!