Hi Donna,
Thanks for visiting the Disney Parks Moms Panel with your question. How wonderful to be planning your first trip to Walt Disney World around such great celebrations!
For character meals, depending on the location, characters may appear at all meals or only at specific meals. I suggest that you look at this
listing of character dining at Walt Disney World. By clicking on the restaurant that you are interested in, you can see information about which meals offer character appearances at each location. For example, you can see that Cape May Cafe offers character dining at breakfast, but not at dinner.
As to the Disney Junior characters, a great way to meet, sing, and dance with them is at
Disney Junior Play 'n Dine at Hollywood & Vine at Disney's Hollywood Studios. You can meet characters from Doc McStuffins, Jake and the Never Land Pirates, Sofia the First, and Handy Manny at this fun meal. This is a character dining location at breakfast and lunch; the characters do not appear at dinner. If your boys really love the Disney Junior characters, while you are in Disney's Hollywood Studios, I suggest that you visit
Disney Junior - Live on Stage!, which is a fun, musical show including puppets and live performers and featuring current Disney Junior characters. After that, you can head out the the Animation Courtyard where you can meet some of the Disney Junior characters. Please do note that character appearances are subject to change.
I hope that these thoughts are helpful for you, Donna. Have a wonderful time planning your vacation, and please do not hesitate to ask if you have any further questions!