A good DJ carries an encyclopedia of music in his head. If you can broadcast your brain to crowds of people, you can do it. Are you on the cutting edge of music technology? Do you have a knack for graphic design, video and social marketing?
If you're an introvert, you're in luck. Let the speakers do the talking; being in the studio means never having to show your face. If you're an extrovert, saddle up.
You should have a good voice, but you won't go very far without professional training. You don't just walk into a recording studio and say "Ford Trucks" a couple times for a big paycheck. You need to create characters with your voice. You need to announce songs and the news appropriately. Are you suited to be a classical DJ or are you better at raunchy humor?