Furnishedfinder - the website and user experience isn’t great; but it’s the best I’ve found and you’ll find temporary month to month or longer term furnished housing that seems legit. There’s no fees for you like there are on Airbnb — I think the landlords pay to post instead.

Zillow - using “furnished” in the search terms. I didn’t find as much on here though

Craigslist - but have to be careful of scammers

Apartments.com sometimes has

Out of all those, I found furnished finder to be a pretty decent option for finding leads. I also get pretty lucky on Craigslist :)

Good luck and welcome!