Hi, Donna!
To find where characters will be throughout the parks in Walt Disney World, download the free APP
My Disney Experience. This APP lists specific information about character greetings throughout the parks. Similar information can be found on the Times Guides which are available just inside the park gates, next to maps.
Next, look at the link for
Town Square Theater in Magic Kingdom as well as
Character Greetings.
At Epcot,
Character Greetings are in several World Showcase locations, as well as at the Epcot Character Spot. At Disney's Animal Kingdom, find
Camp Minnie-Mickey Greeting Trails and additional Character Greeting locations, also listed on the Times Guide. For
Character Greetings at Disney's Hollywood Studios, take a look at that list of possible sightings, too.
Be Our Guest Restaurant will not include character dining at this time; there are Character interactions taking place in and around the
New Fantasyland Expansion, though.
If there is a particular character you just can't leave without seeing, send another question and I'll see if I can tell you where that individual usually likes to greet Guests. :-)