How can i upload games trailer on my channel, I will edit it and will speak on it.

Please tell me full and easy process to upload games trailer with monetization on YouTube, how to take permission fast to upload, where to take permission to upload, to take a real trailer video copy.

Thanks.

If I buy a Xbox One game today, for example. I buy Assassin's Creed Unity today then will I get it bug free with updates and then don't I need patches and updates?