i have this problem that i cant seem to build anything because i cant get the build main menu, i look on the online help, it says i have to click on a square next to a commander, but when i do that nothing happens.

You must first acquire the technologies to build specific stuff, e.g., purchase Militery technology to be able to build a Military Academy and thenafter another barracks or Training facility.
Check out the technologies evolution tree at the warliner site.

ahh thnx a lot!