Hi Brandy!
Congratulations on getting into the Glass Slipper Challenge! That race filled up quickly, and I know it will be amazing!
Your family will be able to view you in different areas. They can come to the starting area, but won't really be able to see much there. Most people like to take the monorails to the Magic Kingdom (during the half marathon), where they can watch their runners come up Main Street USA. No ticket is required since they will have all spectators out before the park officially opens.
You may also look into purchasing chEAR squad packages for your family if you want to enhance their viewing options. You can read about those on the
Princess Half Marathon website, under the tab "SPECTATORS".
For after the race, there will be areas set up for families to meet. There will be signs with letters on them and some benches. Generally, families plan to meet up in the area corresponding to the first letter of their last name.
I hope this helps! Please let me know if you have any other questions.