I suggest finding a niche. You have to know who your audience is. I highly recommend not making let's plays until you have an audience already. No one want's to watch someone play a game unless they are either incredibly good, or very funny. No one will take a chance on watching a lets play unless they know you have one of those qualities. So figure out how you can appeal to a niche group. Pick a game to focus on first, then figure out a unique or at least less common style of video you can make for that game.
Gaming channels are a tough, tough avenue.
Personally with my channel while it is a "Gaming" Channel I don't post much gameplay at all. I make reviews for PC gaming peripherals and hardware. I also build life size replicas of in game Items. Swords, armor, and recently Overwatch guns. As well as make news videos for upcoming titles. Everything I do pertains to gaming, so I would call it a gaming channel. But I found my niche in the gaming world.
Take some time sit down and brainstorm what kind of videos you want to create. Figure out what you will have the most fun doing. If you don't enjoy the videos you make it will come off in the video for sure. Also no one should get into YouTube with the intentions of making tons of money. If you do that's fantastic but it's not easy.
I hope I helped in some way. I am not by any means trying to discourage you. Just know what you are up against and be smart in your video planning.
Best of luck.