Yeah sorry. If you are a child and can’t afford to buy gems you can perfectly well play the free parts of the game (which is plentiful). Will you be able to really compete at multiplayer? Not really, will the levels be very easy because of nice gear? No. But that’s life. It’s the same in most games these days. Free is free but if you want to be better or have your time be easier, you have to buy gold / gems / whatever.