It is free, but starting now has you at a serious disadvantage. Alot of airlines are well established and there are no more gates available, well you get 5 when you start but that's it ;-)
You wont make any money.
That's not strictly true, if you choose other than NA or
EUR gates are availble but the ranges are so long, it is hard to make any money with small planes.
But I would suggest playing the game so that you understand some of the strategy behind the game play. You may not break the top 100 but you will be in a much better position to be a palyer in the next round.