I rarely fly Airtran, but a few things I always have on me when flying:
* Book or magazine. Even if you have an ipod/DVD player/other electronic device, from the time they close the plane doors until you get above a certain altitude (about 20 minutes depending on the wait to get to the runway) and at a certain altitude on the way down until you get to the gate all electronic devices need to be turned off. You'll need something to occupy your time then.
* Earbuds (like for an mp3 player). Some planes have jacks in the seat so you can listen to in flight entertainment. You can generally purchase a set on the plane, but earbuds easily fit in a pocket
To get through security a little easier, wear shoes that are easy to take on/off. You may/may not want to wear sandals with bare feet (since you'll have to walk through the metal detector without your shoes.
If you bring a carryon, make sure a) it fits the size guidelines and b) it's easy to carry/roll. At MCO (if not other airports), you might have to go a good distance from the entrance to the plane, or between planes.
If I think of more, I'll let you know.