I've been to Orlando. It's very hot so take a lot of sunscreen (I got the tops of my feet burnt so my shoes were rubbing all painfully for ages) and bottled water, and it's a good idea to take one of those little portable fans that also spray water.
Get to theme parks early-ish to avoid the rush. Also, they have bag-checks on the way in, in case terrorists decide to blow up the Magic Kingdom just BTW.
The queues can be very long, but if you put a positive spin on that, you'll never complain about queues at a local theme park again! 20 mins is considered really short. Don't bother queueing for more than a few hours, though. The Space Mountain queue was MASSIVE when I went, over three hours, so we just left it.
They have people trying to get you to buy timeshare apartments, which my dad did when we went, because a) the salesman told us that Orlando is the best place to buy on the whole planet, and b) me and my brother wanted to be able to tell people our dad owns a place in Orlando, LOL. We got to go in a limo to Sea World, it was awesome cos everyone thought we were famous...I don't think that was my point, LOL, just any excuse to tell that story.
Also, if you have an immature sense of humour (which I do), look out for the hotel called Gaylord Palms. Me and my brother thought that was hilarious, LOL, and so did my friend who has been to Florida as well.
That's about all I can think of to say now...
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'El reloj, no avanza
y yo quiero ir a verte,
La clase, no acaba
y es como un semestre"