Palmistry is a very legit form of divination. It's different from Astrology, it's not as easy as Astrology initially, and I'd say Astrology gives you a clearer structure, but Palmistry if done correctly can give you shockingly accurate details, about past, present and future. But to become good at it you need an incredible amount of experience, that is harder to obtain since you have to study hands, not charts.
We don't know whether or not the person offering consultations is actually good at his job or he's just a scammer, so there is no way we can give you valid advice. The choice is yours.