Thanks! I've learned a ton from iq's writing. He's such an inspiration!
I find that his articles are best for folks who already know a thing or two about computer graphics. Here's a post that I think is pretty good for beginners: http://jamie-wong.com/2016/07/15/ray-marching-signed-distanc...
For anyone getting interested in distance functions and ray marching, whether it is in 2D or 3D, Inigo Quilez [1] is the authority in this field.
[1]: https://www.iquilezles.org/