Forex and trading involve some risk if you are trading real money. However, you can minimize this by using strategies such as working out your trade size, so you know exactly how much you are prepared to lose, and then always using a stop loss.
If you are not familiar with working out your position size before a trade, and money management, see Using Correct Money Management.
A big myth is that with large leverage comes bigger risk: this is not the case at all. Just because a trader may have 500:1 leverage does not mean they have more risk than someone using only 25:1.
If, however, the trader with 500:1 is using every spare dollar in their account with that leverage in order to make a trade as big as possible, then of course, this is a lot more risk. But the leverage shouldn't matter because both traders should be both working out their trade sizes exactly the same way, and the leverage should not be affecting the outcome of the trade.