tactical and logistic structures

yes there is.

tactical and logistic slot can increased planet specific with the respective upgrades. the type of planet dictates how many upgrades and this how many slots in total you can have. desert planets have the most logistics slots, terran planets also have quite a bit, the come ice and volcanic worlds and asteroids have least.

there is also a tech for tec which increases logistics slots throughout your empire and a tech for advent that increases tactical slots throughout your empire. but as I said, the primary means it on the planet level.

as for fleet size, it is increase solely via research. in the third tab in the research screen, the bottom row indicates the levels of fleet supply you can research. but be careful, every additional level increases the amount of resources lost to maintenance of fleet and fleet structures and it depends on the level researched, not on the amount actually used. so think about whether you really need and you can really afford the next level before you proceed. the first few levels though are rarely a big deal though.

edit: oh yes, and the vasari have a tech that gives them a bonus to fleet supply.

Thank you very much Shadowhal!

I've also tried to build the Tech and Military Temples, but I never understood what was their usefulness: they have nothing in their menu.

Thank you anyway: you were very useful, for i need more fleets for defend my planets against pirates.

Terran = population

ice + volcanic = resources

Desert = logistical slots

np.

I think you are referring to miliary and civilian labs. all they do is grant access to higher levels of research. for example, if you want to build trade ports as tec, you need two civilian research centres in order to be able to research that tech. you also need two (and that's the same with all races) to make ice and volvanic worlds colonisable. and and and. there are fairly big research trees in the game. pick an easy game set up and browse through what each of these techs do, how you could employ them and so on. some of the stuff is really powerful.

oh, research is done via a central menu at the top of the ui and the research menu has several tabs. which I think is a great improvement over building centred research where you always had to search a building and then order etc etc.

you might also want to check out the game manual or the in game tutorial. I'd say these cover a lot of those first questions and get you into the game. the rest you'll figure out while playing.

Might also note that some planets will have bonuses such as 'Weapon Test Facility' that can increase slot counts.  You can't build, wreck or move 'em, but they're nice to find and have.

Regarding pirates -- be aware that the very first capital ship is free once you build a cap ship factory.  A single cap ship should fare well against early pirate raids unless it's been already badly damaged.

UI = User Interface. (the options buttons and different things you use to interact with the game)