Majin: High defense but slow stamina recovery. Defense bonus when stamina is maxed. Stats differ by gender.
Male - more hp but lower movement speed.
Female - higher movement speed but lower hp.
Saiyan: low hp but high attack power. Attack power rieses when hp is low, and all stats rise after reviving.
Male - stronger melee attack and buffs last longer but super moves aren't as strong.
Female - can use Z assists more frequently, better ki and stamina recovery, but lower hp.
Earthling(human): balanced stats for both offense and defense. Ki refills automatically and attack rieses when maxed.
Male - have stronger strike super attacks.
Female - have stronger ki blast super attacks.
Namekian: low attack, but high hp and stamina refills quickly. Items are more effective than other races and hp regenerates when low.
Frieza race: fast speed but low attack. Can paralyze enemies with ki blasts. Speed bonus when hp is low.
Adding to what Tyler said, you can also have a female saiyan, majin and earthling.
You have a very good range of customization and it'll label with advantages/disadvantages.