I am using BabylonJS a lot. If you want to go into 3D Games, it is as of right now the best engine you can get and it's free. In the HTML5 Game Devs Forum the whole community is gathered. They are super nice and helpful. The creators and the main contributers are helping people with questions realy fast!
For 2D games Phaser might be for you. There is also a great community on the HTML5 Game Devs Forum for Phaser. But to be honest I havent really much experience with it.