You should read the beginners guide to construct 2
scirra.com/tutorials/37/beginners-guide-to-construct-2
Even if its not a bingo game it will help you understand construct 2.
But let me get you started.
Creat a text on the layout.
Go to the event sheet.
Event > system > on start of layout
Action > set text > random(1,100)
You just created a random number.