Unless you're already familiar with a tool, I'd suggest starting with the very Hello, world basics.
For Webpack, that's creating an empty project and incrementally adding config, starting with just an entry point (use a simple script importing some modules) and an output filename. Add one loader/plugin at a time. Move into boilerplates once you're familiar with the basic concepts.
(I wish more projects had a Concepts page like Webpack now has: https://webpack.js.org/concepts/)
A boilerplate is another person's code, and while it's good to avoid NIH, unless it's superbly documented, it contains tricks and workarounds that only cloud real understanding.
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Eric wisely started the article with JavaScript & DOM Fundamentals. For people like me, who were familiar with pre-ES6 JS but weren't actively writing JS lately, the basics themselves have changed a bit.