If the timeshare was rented for 14 days or less, you don't need to do anything. It is not income and you've already filed your return.
If the timeshare was rented for more than 14 days, you need to report the rental income on Schedule E.
You'll need to allocate the costs based on the days it was available for rent. Even though you did not use it at all during 2024, if you did not make available certain times, those are considered personal use days. Then, you can prorate the costs between personal and business use. Most ordinary and necessary expenses you have incurred is allowed to be expensed- maintenance fees, cleaning, management fees, etc.
Here is some information you may find helpful: 10 Tax Tips for Airbnb, HomeAway & VRBO Vacation Rentals
