I feel like I was similarly curious a year ago. I think this is a good tutorial for introducing the pieces one at a time: https://github.com/verekia/js-stack-from-scratch

It is opinionated (as in, it picks a single option; webpack instead of gulp, react instead of angular or vue), but I think it does a good job of introducing things in isolation. I ran through the tutorial a couple times after I was more familiar with things.