First...How tall are you? 5'9"-6'0"?
Second, honestly man. Why not go ahead and start training. The best way to condition yourself for MMA is...you guessed it, to train MMA (whether that aspect is Muay Thai, catch wrestling, Jiu Jitsu, Judo, blah blah blah).
A training partner of mine did exactly that, did it every day, did some interval training (about 3 times a week) and dropped about 30-35 pounds in about 6 weeks. He was very strict on his diet so those results aren't typical. But that's my opinion. Just remember, everyone was a 'greenhorn'/beginner at one point. Some guys may not remember that, or be outwardly expressive about such, but many should be able to help out. Diet wise, not sure of your body type other than that basic stats you gave us, but eat a lower carb diet, higher protein and start there. You may want to look up the high-low-low-high-low-low carb/diet scheme on some various sites. I have heard great things about such scheme doing great things.
"It is human nature to find an easy way of doing things. Nothing can take the place of hard work." -Dan Gable
Iowa Wrestling Coach