Could you please better describe what you call “automated formatting”?
Meanwhile you can disable the automatic correction feature, aka. AutoCorrect by going to Tools
>AutoCorrect
>AutoCorrect Options
, Options
tab and uncheck all boxes.
Regarding numbering, tell us what you need: chapter numbering or item numbering in a list? Relying on the built-in numbering features is much more reliable when you edit your document as the items are automatically renumbered to keep a monotonically increasing sequence.
Last, if you really want a plain text document, i.e. a text without any formatting at all, use a text editor. It only records characters and contains no formatting directive.