How should i script the following actions... Thread

Hello all... new hopeful game dev guy here with a question on scripting...

I'm looking to create a wave spawner to drop bombs, that begin a 5 second timer once they hit a surface, showing the user the time countdown, that once time runs out the bomb explodes complete with animation, the wave spawner then detects the bomb has gone and spawns a new one. Upon exploding the bomb is to leave dirt&debris on nearby objects/players, destroy the environment leaving a hole (think of worms bombs eating away at the landscape over time) as well as having a lethal zone where varying damage is inflicted on the player depending on proximity.

Wondering how to structure my code for this, the best approach to get my C# scripts done, all in 1 script or will it be done in multiple scripts ?

for example i have created the wave spawner and it works when testing, so the bombs now spawn from an empty game object, but where do i tell them to explode? in a new script? where do i tell the explosion to do damage to the environment? where do i tell the player to be hurt by the explosion on varying degrees of proximity? a new script for each or?

It's intended for unity 2D game setup for a phone game.

any advice would be much appreciated!

Thanks

Nick