Spawning objects from top of screen, Javascript

Hello,

I'm currently working on a 2D (yes 2D) game in Unity and what I'm needing the game to do is spawn objects from the top of the playing field and then fall into an object at the bottom of the field and disappear. I know how to make objects disappear using collisions but what I'm lost on is how to spawn random objects from the top of the playing field and fall down.

Example: I want an apple to fall from the top of the playing field and into a basket at the bottom of the playing field and disappear.

I'm working with Javascript and I'm just very lost. Help is absolutely greatly appreciated!