I'm a Noob Who Needs Some Help Please

Alright so i've got Kali Linux light version, and i've download top10 packages and some others

Currently i'm downloading MD5 rainbow crack tables. That is not important though.

I need some serious help, as I don't know what i'm doing...

First off I want to know, when I crack a hash/password what can I do with it, like how can I use that to access someones account on a text based game or whatever?...

I have many more questions, yes i'm a complete noob! But I want to understand that first, then maybe I can use my brains to apply it once I know what to do with a cracked hash.

Thanks