Need help finding the right terms for what I'm trying to learn: Web Development [closed]

I want to understand web design/architecture from the ground up but 9/10 times the information I get back is just "Learn HTML/CSS/Javascript". I want to know more about the principles and methodologies of web design. What each little part is.

I've looked around my college I graduated from and they don't offer anything except HTML/CSS at a 300 level course, and introduce javascript for DOM manipulation in the 400 level course.

I was hoping someone knows what it is that I'm trying to find? I want to formally understand and learn things like one would in a classroom setting more or less rather than piecewise picking parts up as i need them everywhere.

If that isn't as confusing as it is for me to describe I more or less want to understand how web technologies work, how http requests work, what exists currently, how to implement some, etc. I don't know the right terminology for what I'm trying to find either so it's making google searching a bit difficult.

I've put together a makeshift airline website in college where I used java servelets, then redid it using PHP instead, but I honestly don't know what half the things I was doing/using were and I'd love to better understand what they are as a general topic rather than specifically, how/when to use them, etc.