Just want to automate minifying simple client-side websites - how do I accomplish this with minimal dependencies in 2017?

I develop custom SPAs that require little/no server interaction aside from serving static files. My sites end up with 1 html, css, and js file each. I've been manually copy/pasting minified code using http://lisperator.net/uglifyjs/. I'm trying to improve this process. Given this info, is there a clear path(s) I can take to automate the minification of my files whenever the source is updated?

So far, I've installed Node.js (I assume I need this?) and used NPM to install Uglify and Nodemon... But I don't know what I'm doing.

I know Gulp is popular, but I've read that for my limited requirements, NPM scripts are all I need (whatever that means). Also, Webpack? I hear it's closely associated with React, which I don't use. Vanilla JS, Vanilla CSS, Vanilla HTML and so lost...

Forgive my noob question, and help me improve it if necessary, for others lost like me: https://hackernoon.com/how-it-feels-to-learn-javascript-in-2016-d3a717dd577f

via calipoop