A webpage is just a text file
Every website you've ever visited started as a plain text file on someone's computer. Your browser downloads that file and turns it into the visual page you see. That means you already know 90% of how websites work: they are files that describe what to show.
analogy
Think of a recipe card. The card is text — 'add flour, mix eggs'. The kitchen (browser) reads the recipe and produces the cake (webpage) you actually taste.
why it matters
Once you see the web as text describing content, it stops feeling magical and starts feeling like something you can build.