Need advice for learning app development with Elctron framework

I have learned the basic HTML, CSS, JS course through w3schools.com. I picked up a few frameworks like Bootstrap, jQuery, and Angular along the way (though not too much). The main point being, I know only the very basics.

My question is, what else do I need to learn in order to get cross-platform hybrid web apps up and running using the Electron framework?

I don't want to spend too much time learning and, at the same time, I want to know enough to be able to build what I want. To be honest, I haven't built any kind of web app yet other than simple websites with no backend.

Any advice on how to proceed is greatly appreciated; and links to free/quality material will be a big plus!

Thanks!