The game clearly indicates what you should do next.
If you are on the map but cannot construct, it means that you have to enter the R+D Center to create and answer questions. The game will tell you when you are out of options, and you will begin investing your GCoins in constructing and evolving your buildings. If the “Next Turn” button does not work, it means that the season has finished, and you will have to wait for the next one to begin.