How should I prepare for mma?

Im gonna start mma around july because we are moving to fort walton beach this summer. And i was wandering how I should get in shape for it. Im doing crossfit now and lifting weights, I have some boxing gloves and wraps. What other stuff should I be doing to get ready? Im kind of a big kid, Im 6’2" and 198 pounds and Ive got fat to lose. So also what diet is good for mma? Paleo?