You can buy tickets on external websites, like the discount type sites but i would recommend waiting until you figure out exactly what parks you want to do (ie Magic Kingdom, Epcot, Animal Kingdom, etc), how many days you will be in Orlando area, etc. I am not sure how the refunds work on those types of sites, if you had to do one. there are so so so many options to buy tickets, like a one day, two day, three day etc pass to just the parks, then there is a parkhopper pass, then there are the water parks affiliated to each one of the parks, then there are outside parks like Universal Studios, etc. You have lots of time until your trip to do your research, so depending on your length of stay and budget, you can make your decisions either before you go, or when you get there. You can buy passes at the Kissimmee Walmart off Hwy 27, just 5 min from our friend's parents house. Whatever you do, PLEASE do not buy tickets from those tourist kiosks/little shops. They are partially used passes and may not work. You spend a fraction of the money yes, but those passes are unused time from other people. Because the scan cards (passes that you buy) are registered to you with a fingerprint scan, it will be very hard to get in with someone else's pass and you will be out your money.