I am not a tax professional,, but have learned a lot from books and podcasts.. A good book to read "Tax guide for short term rentals" by nolo, my husband and I are considered sole proprietors so we file on schedule E. You will need to check with your State Dept of Revenue for short term rental taxes , you most likely will have to pay a sales and use tax monthly based on rents received, VRBO and Airbnb remit taxes for you in some States.
You will only be able to write off start up expenses up to a specific amount(?5,000), prior to having your property available for rent. Once you have advertised it, ready to rent , you can deduct expenses, furniture is usually depreciated but with new tax laws, I think you can take more deductions in the same year vs. Depreciate.
As far as I know, this is still consider passive income so I do not consider myself self employed . Like I said, I am not a tax professional, this is just what I have learned on my own, so maybe we will hear from a real tax expert .