still going through the various scripting tutorials, there was a cool one to make a 2D game world too
but at the moment i really want to make a parallax background system and test it out with simple shapes
keep in mind the shapes will, in the end, be adobe illustrator output files (probably .pngs)
trying to make something similar to FEIST
multiple gui textures in different distances to camera and moving them appropriately to their “distance to cam” would do that.
there is no tutorial for unity on that topic but 100+ on the topic in general on the web 
and feist likely has no parallax scroling or alike. They have real 3d objects in various depths and use a normal camera instead of a orthographic one → automatic parallaxing