For the image generation (or even indexing with the CLIP interrogator) side of things, recommend just installing the AUTOMATIC1111 github repo (https://github.com/AUTOMATIC1111/stable-diffusion-webui), it's a web ui with pretty much every variant of stable diffusion you could want to try out, like txt2img, img2img, inpainting (both textual inversion and dream booth), outpainting, style customization, clip interrogation, etc. Most importantly, there are about 1000 youtube tutorials on how to do each of these things with it, so you can pick your interest areas and just try it out without having to understand all the details first.

From there, if you're interested in how it works, I highly recommend the last 4 videos on Jeremy Howard's youtube channel: https://www.youtube.com/user/howardjeremyp/videos

He's currently teaching a class on stable diffusion from the ground up and these lectures give a really good introduction to how it all works.