Hi, Steven!
Wow, you have quite the group traveling to visit Walt Disney World! Rest assured, Mickey and his pals have thought of everything to make sure your trip runs smoothly!
To begin, make sure each travel party has a My Disney Experience account at
www.disneyworld.com. Right on that site, you can "Add a Guest" under "Friends and Family." This step will be important later, but let's start with your rooms!
You will need to decide on a resort, and room type. When each party books online, there will be a question asking if you would like to be near another party. If booking by phone, let the Cast Member know you would like to be near your travel party. Make sure you all book the same room type, as it is difficult to be near your travel pals with different room types. Remember that requests for connecting rooms or even exactly next to each other cannot be guaranteed.
Now for your dining reservations. You will want to call Disney Dining at (407)WDW-DINE for your reservations. The online system will not allow you to book a party of that size. I suggest buffets for large groups so there is something for everyone at your special meals.
For FastPass+, you can do that online. Since you will be linked through Friends and Family, you can book all the same attractions and times, or you may want to branch off here since the younger kids vs. teens or adults may enjoy different experiences.
You will want to familiarize your travel companions with the My Disney Experience area of the website so each party can book rooms, change their FastPass+, do online check-in, and order MagicBands. Do not take this all on by yourself, or you will become a full-time travel planner!
When in doubt, call (407)W-DISNEY (407-934-7639) and a Cast member will walk you through! Good Luck!