Your comment is making me reevaluate what I thought I understood.
If you're writing a paper for publication in a journal, they probably have their own typesetting style. With LaTeX you can just specify your paper as a sequence of paragraphs, "sections", a title, an author, and so on, and, by including the journal's style file (assuming it's good), your paper will come out typeset in that journal's style. This philosophy is explained at https://www.latex-project.org/about/
This is great for certain (many) kinds of documents. The problem with this, though, is that the moment you want to change the appearance and get into typesetting yourself, you're fighting a system that was actively designed to prevent you from doing this.
An analogy may be a system like, say, WordPress: if what you have is a blog, then it would work for you, and you even get to choose one of several “themes” that others have written, and so on. The set of available plugins and customizations can even be impressively versatile (for example, I noticed that time.com runs on WordPress, and apparently so do a number of other non-blog sites: https://vip.wordpress.com/clients/). But ultimately, if you're trying to figure it out by yourself and have your own ideas about what your website should look like, a system like this will always be more frustrating than the alternative (of having full control).
TeX is not difficult to use, though in the beginning you'd have to specify manually things like the typesetting of the document title (put it in a bold font at 16pt, centered on a line...). LaTeX has features to automate many such common typesettings tasks, but it has its own flaws (some stemming from the fact that it's implemented using TeX macros, which weren't designed for such heavy “programming”).
If all you have is a passing curiosity though, you may just want to look at some examples: Knuth has .tex sources of some of his papers on his website (https://cs.stanford.edu/~knuth/preprints.html); you can look at them and compare with the resulting PDF files (which you can generate with `pdftex`). For an already typeset example, look at JRM2680.tex (https://cs.stanford.edu/~knuth/papers/JRM2680.tex) and JRM2680.pdf (https://cs.stanford.edu/~knuth/papers/JRM2680.pdf).
You don't say "make a heading", you say "make this text in 14pt font, bold, with this much extra vertical space.
Folks are also highly scared off of TeX due to some of its aesthetic nature. Specifically, it looks rather different than most modern languages.
That said, I think most of that fear is unfounded and I regret that I let it keep me from learning this while in college.
By the way, a really excellent book for (plain) TeX is A Beginner's Book of TeX by Seroul and Levy: it's truly for the beginner, yet at the end you'll be practically an expert, or at least know how to become one.
I've seen people get frustrated with LaTeX (not TeX), but that's because it was designed to make it difficult to do typesetting: instead the LaTeX philosophy is to specify only the document structure, and leave all the typesetting to a package that you hope someone has written.