>If you want to go beyond the "hello, world", I highly recommend this huge series: https://www.youtube.com/channel/UCSnyjB_8iVxi2ZAfn_1L6tA (it's up to episode 130-something now... but start at the beginning!)
Playlist link for the series: https://www.youtube.com/watch?v=LtFujAtKM5I&list=PLMinhigDWz...
After grokking the basics of WebGL I was stuck at where to go next. I could draw triangles, and I could give them perspective... but I didn't know how to combine them into something bigger. The Sketchpunk series was really good at showing how to build it into a library and make real projects.
I used that knowledge to make this minecraft-y thing: https://github.com/mrspeaker/webgl2-voxels (which I especially love as it doesn't use any compilation/build steps - just native modules and plain ol' javascript!).