Guppies are indeed a hardy fish yes and breed very easily(almost too easily, and fast too!)when put in with a male but they still require clean, dechlorinated water like any other fish. Keep your ratios at 1 male per 3 females because males are very pushy and horny and often stress out lone females so a group spreads out the stress. But if your new to the fish hobby, i wouldn't advise getting both sexes as you will be overloaded with 30-45 fry every month! Do you have enough space for that?