This little book had some stylistic and practical advice:
https://www.amazon.com/How-Write-Light-Novels-Webnovels-ebook/dp/B07WRMJ663
though not much on the business side of things so you'll be on your own as far as getting published. Like other have said, LNs are not really made in the West (though they are marketed here) and the chances of getting published as a foreigner in Japan or China are probably not very good.
There is a translated guide about how Chinese webnovelists do it with advice specific to writing webnovels:
https://www.webnovel.com/book/book-of-authors_10589139205070105
There's also a book called How to Write Light Novels and Webnovels for sale on Amazon. There are no startling insights in it, but if you haven't read anything on the subject, you might learn a thing or two.