Saiyans
The Saiyans are a naturally aggressive warrior race who are supposedly the strongest warriors in the universe. They were all but oblitered by frieza. But because of certain circumstances. They have returned and are alive and well on the Planet Bardock.
Nameks
Also commonly known as Namekians, are a race from Planet Namek. There Planet was also destroyed by frieza. Since then they have been given a new namek by the dragonballs and have lived peacefully their for over a thousand years.
Humans
Sometimes referred to as just Earthlings are the main inhabitants of the planet Earth. They share the planet with other intelligent lifeforms, including anthropomorphic animals. In fact, they are lead by an anthropomorphic dog named King Furry VI. They have battled against many enemies and have always been saved by the legenday goku. Now they are giving birth to their own warriors to defend the planet if need be.
Android
They are robotic/cyborg humans, most of them created by the evil scientist Dr. Gero. But as time went on the some humans began to get smarter and develop these cyborgs for their own personal gains. Most of the androids are said to have unlimited energy and have eternal life, as well as having no aura (unlike Saiyans, Humans, and others) so nobody can track them with either Scouters or Ki Sense.
Majin
The original Majin was created by the evil Bibidi. Later on people discovered that he was not the only majin. A plethora appeared on the planet earth and they came in different colors and shapes and sizes. Now they peacefully live along side the humans.
Changeling
They were a race of aliens who were able to drastically change their appearance and make their power level skyrocket. Their names are derived from the negative temperatures on their planet.
Tuffle
They are a highly advanced technological race of beings native to New Plant. They live alongside their experiments. Technically they are an ally for good but some seek revenge on the saiyans for the wrongdoings that happened in the distant past.
Demons
Demons are evil creatures who enjoy using their power to torment, torture and/or kill those who are weaker than themselves. Demons usally are bulk, grey/green/blue, and have three toes on each foot. Most of them live in the Demon World under the leadership of evil-hearted deities called Makaioshins.
Each race have their own strengths and weaknesses, so choose wisely!