How do I

Hey guys!

I am new to this and have stumped myself on this one aspect of a game I am trying to make.

The game simply consists of a ball and three blocks that drop randomly. The ball can move left and Right, but when you hit a block the game ends.

I have absolutely no idea how to make blocks drop at random, at a rate of one droping per 2 seconds. How do I do this?

Thanks!

I seem to have been able to create a random variable function, but no idea how to make it correspond to the blocks and determine which one falls