You will figure it out.  

I will figure what out ? 

Yeah they mean waste your money or get nothing like most players. These devs are cheap and nasty. They'll never make the game for free play like they advertise

I spend $10-20 a month because I enjoy the game.  Others are strictly free play.  It just takes some time to learn how to manage resources.  This is a marathon.  You cant have everything you want instantly, unless you want to spend.  

Most promo code are only good for a week at best.

There's a pinned thread on the discussion page for promo codes, and no matter where a code was announced (discord, YT, facebook, whichever) the community here is really good about posting it in that thread. Just check it once a day or so. Codes *usually* tend to be about 1/month