Thanks @ross.grams, I queued some of the videos recommended and made a list of the written materials. I think I’ll just go through the book I mentioned while I tinker with the tutorials and see how it goes.
And for the cubemaps I found:
https://forum.defold.com/t/still-need-cubemap-sample/52795
https://forum.defold.com/t/how-to-make-a-skybox/16800