After a day of travel you will probably be tired and if you have children traveling with you they could be grumpy. How early is early afternoon?
My suggestion would be, since you are booked at the MCO Hyatt, just stay put. By the time you arrive at MCO and get your luggage then check in you may find it is going on to a point where you can just appreciate staying put. The Hyatt has a pool on the roof, why not just decompose and have the family enjoy that? As far as meals, you have tons in the airport. Are you familiar with the MCO Hyatt? If you are then you will know that there are tons of quick service locations such as Chic fil a, Panda express, Quiznos. There are some sit down restaurants as well such as Macaroni Grill. Everything you need is right there, no need to go outside at all. We use their day room rates just for these factors. Its easy to relax and enjoy, its all right there.
If you are interested in going out the options listed by others are very good. Keep in mind, even with an Uber the cost of going to Disney for the afternoon is not cheap. We have taken several Ubers from Universal and it has ranged in the area of $35 to $40 one way and Disney is farther than Universal. The Florida Mall is fairly close if shopping is your thing however I have found most of the stores in the mall are the same stores we have at home so no big deal IMO.
What ever you decide have a great time.