Hi Patrice!
Thank you for bringing your question to the Disney Parks Moms Panel!
There will be certain items you can pre-order during registration to ensure that you get them. But, there will be many (many) more items available at the Health and Fitness Expo when you go to pick up your race packet. The downside to pre-ordering most of the things is that you can't see them first. But, if you have your heart set on a certain item that is available to order in advance, you should do it.
During Princess Half Marathon weekend, ALL of the
Walt Disney World Resorts are host resorts and will offer bus transportation to and from every event. My favorite resorts are the
Deluxe Resorts because of their close proximity to the parks. The perfect resort depends on your budget, whether you want to spend a lot of time in parks, and which park you prefer to be closest to. Honestly, all of the resorts are clean, nice and well-themed.
I would recommend signing up for the 5K first. That race doesn't have nearly as many runners as the half marathon, so it generally fills up pretty fast.
I hope this helps! Please let me know if you have any other questions.