I wrote an article on learning web development, might be useful to you. Here's the link: https://medium.com/career-change-coder/how-i-broke-into-web-...
If you're only looking for high-level concepts, Crash Course has some good episodes about the workings of the internet.
I know a common architecture is JS in the browser making requests to the server and receives JSON and then renders it somehow. Sometime the server renders stuff itself and sends it to the browser, right?
And then there's possibly a database attached to the server.
How does all that work?