Basically as I understand it, you get "partnered" with youtube as a standard thing to post vids and such and with that you eventually get thumbnails and stuff like that, just ordinary things but you shouldnt monetize your gameplay. Monetization comes as a feature with YT so if you make entirely new content you can start getting the money in straight away. But if you are a gaming channel or using someone elses work or content, you go through a "partner" like RPM or Fullscreen so they can represent you to gaming publishers and to YouTube and they take a percentage so you can legally use their works with your own commentary and you can take the majority cut of what you make from those vids.
Hope that makes some kind of sense
