Ashely, I didn't know they had free dining in March. I've only heard of that offer in the fall - learn something new everyday!
Not positive about today, but I believe you need to purchase at least one ticket (for one day) in order to get the DDP. At least, my parents did two years ago. It worked out for us because MK was on blackout, so we used that day for MK and then I used my Maingate for the rest of the week. I was told that the only exception to the rule are DVC members, they can get the DDP w/out any tickets. But things change a lot and my info is old now.