Being 22 I also started my trading with family money through my dad. My first day last year starting October was terrible, I didn't have enough experience and the market had changed compared to what it was the 2 months before. Was overconfident and ended up blowing up 30% of the account [lost 1500] 500 of it fees to suretrader using huge size on day one and since then I have changed my strategy completely. I wish I would have lost my own money, losing my dads money made me feel terrible for months, even with his salary. Starting again in December I'm going to be risking a lot less, and once I've made around 300 dollars will be jumping up in size. It's best to trade small, make money and then risk the money that you've made in the market. I'm imagining you'll feel the same if you lose your grandpas money. I've warned my dad though, even with how much better I've become trading consistently is not easy. I told him to be prepared to lose 2500, but he's fine with it because he thinks I'm going to make it eventually. Just remember to say the golden rule, which is past performance isn't indicative of future returns and to be prepared to lose some money. I can't stress enough about not upping size immediately with his money, even if he's urging you to.