Welcome @Ghengis Khan you will love it here, there is a lot of information about the game around. Pssst, Pssst: do not research, for now, the optional Squad Size Upgrade (one the ones that you must, you will know). In six months, you will decide whether to do it or not and probably, you will be the few lucky players that did not research a lot of those. Have fun!
Don't worry, you will have space problem only until chapter XVI for now (note: the game has 16 chapters), but you will always manage!