"What are the mistakes that you see or hear about people making the most? What would you warn first timers against?"(source)
There is such a thing as too much planning! You don’t want to miss out on any magic by trying to see everything in one go! Your first WDW holiday should be all about the experience, soaking up the atmosphere, really enjoying your time there.
Yes, you should know the difference between counter and quick service, and that going for Christmas will be magical mayhem! Knowing all about fastpass and photopass comes in handy too. But do not overkill your itinerary! Frog marching from park to park and sticking to a regimented schedule means you will be missing out on many magical moments. Take a seat on Main Street USA with a bucket of popcorn on your knee listening to the Dapper Dans. Spend a whole day away from the parks, lounge around the hotel pool, go for a round of mini golf or explore the other Disney resorts.
You need to have some knowledge and an idea or what you want to do, but for the better part of the trip just go with the flow. Bogging yourself down with guidebooks and touring plans leaves you feeling as though you’re studying for a Disney Degree! They can tell you all you need to know, but the magic is in the experience!
If your itinerary says you’re heading to Epcot the next day, but you really fancy going to Animal Kingdom – do so! Head off the beaten guidebook track and start creating your own magical memories!