Coding in Java in Android Studio

I need help coding something in Android Studio and Java. I am making an app that is sort of like what was used for Ayumu the Chimp (https://www.youtube.com/watch?v=JkNV0rSndJ0). I have created the start screen and creating the numbers in their initial positions. However, my problem is randomizing the positions of each number. How would I go about doing that? Also, how would I go around creating a timer to count down until the numbers are covered? And how would I cover them? The numbers are in textViews, by the way. Thank you in advance, Son of a Genius