If you are an ordinary producer of documents (plain text, articles,tech reports, letters, mathematical documents, etc.) you should start with LaTeX, not TeX. I

If you are an ordinary producer of documents (plain text, articles,tech reports, letters, mathematical documents, etc.) you should start with LaTeX, not TeX. It is uncommon to write in plain TeX and this has been so for many years. In practice, you will use mostly LaTeX constructs, and the simplest TeX ones, which the LaTeX guide would include.