One issue you'll probably run into is that format options are usually set by your filetype plugins. These are global plugins installed with your vim install and they load after your normal vim startup config, meaning they will override your setting if you just try to globally set formatoptions.

Instead, you can place your formatoptions in your local filetype configs: nvim/after/ftplugin/text.lua for example.

letter	 meaning when present in 'formatoptions'

t	Auto-wrap text using 'textwidth'

c	Auto-wrap comments using 'textwidth', inserting the current comment
	leader automatically.

r	Automatically insert the current comment leader after hitting
	<Enter> in Insert mode.

o	Automatically insert the current comment leader after hitting 'o' or
	'O' in Normal mode.  In case comment is unwanted in a specific place
	use CTRL-U to quickly delete it. i_CTRL-U

/	When 'o' is included: do not insert the comment leader for a //
	comment after a statement, only when // is at the start of the line.

q	Allow formatting of comments with "gq".
	Note that formatting will not change blank lines or lines containing
	only the comment leader.  A new paragraph starts after such a line,
	or when the comment leader changes.

w	Trailing white space indicates a paragraph continues in the next line.
	A line that ends in a non-white character ends a paragraph.

a	Automatic formatting of paragraphs.  Every time text is inserted or
	deleted the paragraph will be reformatted.  See auto-format.
	When the 'c' flag is present this only happens for recognized
	comments.

n	When formatting text, recognize numbered lists.  This actually uses
	the 'formatlistpat' option, thus any kind of list can be used.  The
	indent of the text after the number is used for the next line.  The
	default is to find a number, optionally followed by '.', ':', ')',
	']' or '}'.  Note that 'autoindent' must be set too.  Doesn't work
	well together with "2".
	Example:
		1. the first item
		   wraps
		2. the second item

2	When formatting text, use the indent of the second line of a paragraph
	for the rest of the paragraph, instead of the indent of the first
	line.  This supports paragraphs in which the first line has a
	different indent than the rest.  Note that 'autoindent' must be set
	too.  Example:
			first line of a paragraph
		second line of the same paragraph
		third line.
	This also works inside comments, ignoring the comment leader.

v	Vi-compatible auto-wrapping in insert mode: Only break a line at a
	blank that you have entered during the current insert command.  (Note:
	this is not 100% Vi compatible.  Vi has some "unexpected features" or
	bugs in this area.  It uses the screen column instead of the line
	column.)

b	Like 'v', but only auto-wrap if you enter a blank at or before
	the wrap margin.  If the line was longer than 'textwidth' when you
	started the insert, or you do not enter a blank in the insert before
	reaching 'textwidth', Vim does not perform auto-wrapping.

l	Long lines are not broken in insert mode: When a line was longer than
	'textwidth' when the insert command started, Vim does not
	automatically format it.

m	Also break at a multibyte character above 255.  This is useful for
	Asian text where every character is a word on its own.

M	When joining lines, don't insert a space before or after a multibyte
	character.  Overrules the 'B' flag.

B	When joining lines, don't insert a space between two multibyte
	characters.  Overruled by the 'M' flag.

1	Don't break a line after a one-letter word.  It's broken before it
	instead (if possible).

]	Respect 'textwidth' rigorously. With this flag set, no line can be
	longer than 'textwidth', unless line-break-prohibition rules make this
	impossible.  Mainly for CJK scripts and works only if 'encoding' is
	"utf-8".

j	Where it makes sense, remove a comment leader when joining lines.  For
	example, joining:
		int i;   // the index
		         // in the list
	Becomes:
		int i;   // the index in the list

p	Don't break lines at single spaces that follow periods.  This is
	intended to complement 'joinspaces' and cpo-J, for prose with
	sentences separated by two spaces.  For example, with 'textwidth' set
	to 28:
		Surely you're joking, Mr. Feynman!
	Becomes:
		Surely you're joking,
		Mr. Feynman!
	Instead of:
		Surely you're joking, Mr.
		Feynman!