5.1 How do I set up an init file properly?

When Emacs is started, it normally tries to load a Lisp program from an initialization file, or init file for short. This file, if it exists, specifies how to initialize Emacs for you. Traditionally, file ~/.emacs is used as the init file, although Emacs also looks at ~/.emacs.el, ~/.emacs.d/init.el, ~/.config/emacs/init.el, or other locations. See Init File in The GNU Emacs Manual.

Emacs includes the Customize facility (see How do I start using Customize?). This allows users who are unfamiliar with Emacs Lisp to modify their init files in a relatively straightforward way, using menus rather than Lisp code.

While Customize might indeed make it easier to configure Emacs, consider taking a bit of time to learn Emacs Lisp and modifying your init file directly. Simple configuration options are described rather completely in Init File in The GNU Emacs Manual, for users interested in performing frequently requested, basic tasks.

In general, new Emacs users should not be provided with init files, because this can cause confusing non-standard behavior. Then they send questions to the help-gnu-emacs mailing list asking why Emacs isn’t behaving as documented.