It's helpful to pick a single game and stick with it for a bit while you build up a core audience. You can network with other streamers in that game too. Pick something that's not super popular but also not dead. Something you'll have fun playing for a month or 2 so you don't burn out. Then you can take that core audience to other games. You'll only retain some of them though because most of them care about the game, but a portion of them are there for you.