Spend some time getting used to the intensity and the exercises, learning the movements. For different people that will be different lengths of time.
Once you feel comfortable with the regular cycle, start emphasizing the Max effort days. I do atleast one ME day per 3 day cycle. I still want the Met.con. that comes with the reg. crossfit routine. Check out Michael Rutherfords Max effort routine.
After a year Crossfitting, I've crept over the 265lb. mark, which is not what I wanted, but my performance still seems to be increasing.
I can give you more info. if you like.