Qualifications
A Ph.D. is required for this job. You must first have a 4.0 grade point average and SAT scores in the ninetieth percentile. Don't forget about the certification from Johns Hopkins.
Wouldn't that be silly. No, none of the normal educational qualifications apply here; you just have to punch and kick and choke and slam until you win, and then do it a bunch of other times. If you do that, and manage to secure yourself a manager or promoter who continues to find you tougher and more prestigious opponents, you can go far.
This is the time we should tell you that it'd be a good idea to learn a real martial art before you step into the cage. You may be really strong and tough, but if you walk in there and just flail your arms about, your opponent will eventually land a swift kick to your jaw and send you to the emergency room.
Speaking of training, why not also go to school for something? You know, maybe nights while you're not training? Having a college degree might be good backup, just in case you get beat up a lot and have to find some way to make money while working from home and barely moving.