My very first trip, I was totally overwhelmed too. I'll tell you what I did. I bought the Unofficial Guide to Walt Disney World. In the back there are touring schedules. I picked the one the best suited us. I made a copy of each of the schedules that we wanted to follow. I studied the maps so I knew where to find things in the parks -- and I went forward. My DH says that even our bathroom breaks were part of the schedule. But, all in all, we saw and did so much during that trip, that he was amazed. Of course, when we got back home, we needed a vacation. But, it was a plan and it worked.
My major piece of advice -- arrive at each of the parks before they open in the morning. You will get so much done during the early hours than you will for the remainder of the day -- especially in the summer heat. That way, if you get overheated, you won't mind returning to your hotel room for a bit -- because you have already hit the major attractions.
Since then, we have become old pros -- with 30 plus trips under our belts since 1990 and still discovering new favorites.
The most important thing is to have fun.
