Hi Maria!
Welcome to the Disney Parks Moms Panel. As an engineer, I am all about the spreadsheets girl so I totally wish something like that existed!
You have a couple different sources you can use to try and figure out where the characters are, but the character meets at Walt Disney World change very often so even if a sheet existed it would be outdated fairly quickly. Your first option is to review the
character meetings on the Walt Disney World website. This tends to be characters that are fairly consistent and have permanent homes or meals.
Your second option is to use the
My Disney Experience mobile app and click on the bar across the top that shows Characters. This is live though, so at the time I'm searching Magic Kingdom is the only park that is still open, so it's the only one showing characters. While this can change and could be different on the day you visit, it should give you a fairly good basis if there is a character that you must meet!
The resource I use quite often is an unaffiliated blogger known as Kenny the Pirate. If you Google search for his website, he has an extensive list of every character and when/where they are traditionally available to meet. While this is not a guaranteed source, I've found it to be very accurate on my trips, especially for the rare characters you may only meet at the special events, like
Mickey's Not So Scary Halloween Party or Mickey's Very Merry Christmas Party.
I hope this helps you track down those characters you just can't miss! Please let me know if you have any other questions before your trip.
-Lindsey ºOº