How do you create a constantly spawning set of random missiles that move vertically down?

I was wondering how I would create a set of randomly spawning missiles at the end of a picture, that travel vertically downwards, and with contact with the player, ends the game. I would greatly appreciate some help. Thank you in advance, Anish.

(If possible, with time could these missiles increase in speed and quantity?)

What do you mean by “at the end of a picture”?

Your question is too broad to be answered here. But I suggest you start by following a tutorial that will teach you all you need to know to learn how to do all that.