A visual clue to a Characin is that it will have an adipose fin. That’s the little fin on top behind the dorsal fin and just before the tail. Apart from the predatory species such as the Piranhas, most are peaceful even if carnivorous.
They will usually readily accept aquarium foods like flakes and tablets, as well as enjoying supplements of brine shrimp and various types of worms. They usually prefer clear, slightly acidic water with strong currents and highly oxygenated.