In that case I should also mention that Blender is 100% free to use forever (free and open source software ftw!!) and that you can hardly throw a stone on YouTube without hitting a tutorial on how to use it.

Here's a video about how to make fractals using geometry nodes: https://youtu.be/N9Tnmbnl9Yw

And here's one listing every shader node: https://youtu.be/cQ0qtcSymDI. Keep in mind that these can be combined with virtually no restrictions on what you can plug into what!

In essence, geometry nodes build procedural 3D shapes and shader nodes decide what color they are, how reflective they are, whether they emit light etc. You can also apply these factors to only part of the geometry in procedurally generated patterns.

You can either build the geometry by hand and then slap some shaders on top (I like just slapping down a flat plane or a cube or w/e with some stuff next to it for light to bounce off of and seeing what cool things I can do with it) or go fully procedural and use geometry nodes too

I will warn you though that the interface outside of the node editors is not especially intuitive (nothing could be, with the amount of controls Blender has) and you do need a somewhat beefy computer for Blender to perform well, especially if you plan on using the fancier graphics features like raytracing (which I highly recommend -- the Eevee renderer which uses rasterization instead is orders of magnitude faster but the lighting and reflectivity does not look anywhere near as good. Fine for actual 3D animation but if you want to play around with a light synth, Cycles is 100% the way to go)