npm-init man page
npm-init — Interactively create a package.json file
npm init [-f|--force|-y|--yes]
This will ask you a bunch of questions, and then write a package.json for you.
It attempts to make reasonable guesses about what you want things to be set to, and then writes a package.json file with the options you've selected.
If you already have a package.json file, it'll read that first, and default to the options in there.
It is strictly additive, so it does not delete options from your package.json without a really good reason to do so.
If you invoke it with -f, --force, -y, or --yes, it will use only defaults and not prompt you for any options.
The scope under which the new module should be created.
npm help 5 package.json
npm help version
npm help 7 scope