Dispatchertimer coding to change images within one image box

Hi everyone.  I am very new to programming.  I am trying to self learn.  I decided to try develop a program for my kids and got a little stuck.  I am using Visual Studio 2019 WPF app in C#.  What I am now trying to do is set an image box to change images after a given time.  One image box will have to show 26 images.  Im not too clued up with the terminology yet as I am still trying to learn.  I would greatly appreciate any assistance.  Thanks.