Betta fish are perfectly fine beginner fish in the right environment. Males are only extremely aggressive towards other males (or fish that closely resemble other males). Otherwise, they are shy and prefer a small, quiet tank. Betta fish survive in very small, difficult spaces in the wild. They are tough fish, but many people abuse their ability to survive in less-than-ideal conditions. Vases and other novelty containers should never be their permanent homes. A small, two to ten-gallon filtered tank with shrimp, snails, or other peaceful community fish makes a perfect setup for bettas. The list I have provided is by no means exhaustive. There are plenty of other great beginner fish. Just do your research to see if they will work in the aquarium you have.