Flipping a Home

I'm trying to figure out how I can deduct or write off all of the expenses including mortgage interest, insurance, repairs, utilities, etc....   The courts awarded my ex husband (from years ago) to sign over his house to me in March 2023. It is 5000 sq ft fully hoarded to the ceilings. I had to catch up the mortgage and it has taken me this long to get it cleaned up and hopefully I will get it listed for sale March 2024. It will be over a year. I don't know if I can list it as a rental property as I never rented it or if it needs to be listed as a second home. Also I am not really sure how to document how I acquired it on turbotax. Do I just mark that I purchased it March 2023 and mark the market value as of that time?  Is there a tax break on capital gains for investment vs second home? I have had to put a lot of money into maintaining this home ($3000 per month house payment) and thousands into cleanup, repair and improvements trying to get it ready for sale. Thanks for help