I'm new to ALL this

Hello! First of all, I'm really sorry if i'm not allowed to post this kind of Threads, or if this is not the correct section to do it.
The thing is that i'm completely new to Hashcat/oclHashcat, or any password cracker in general. I have no idea what a Hash, or Mask is so I guess that i'm completely lost. I have decent understanding and knowledge of programmaing... I dont know if that helps.
I've really been trying to find an easy/simple video tutorial, or written tutorial, and trying to understand what a Hash is, but i'm not getting much from it. I would REALLY apreciate if you could give me an easy tutorial/guide.
English is not my first language, sorry if I expressed myself poorly.

I'm just asking for some tutorials/guides so I can study from that, or any advices related to where can I get started...

BTW: I was trying to crack the password of an account a I've had for a long time in a game, but I forgot the password. It really doesn't have a decent security, I don't know if that helps. Well, will it be possible for me to recover my password? The game doesn't offer any other way to do it.

Thanks for the attention guys!