What you recevied in the way of physical cash is irrelevant. Your sales price is the price you sold it for as documented in the sales contract between you and the buyer.
no money came to us at all, mortgages were paid off
That's totally irrelevant. The mortgage payoff is "NOT" tax deductible. In fact, it's exactly the opposite and is reportable income that was paid to you. The fact you used that money to pay of the mortgate doesn't matter. Most likely it's taxable income to you. But that depends on your sales price as it relates to your cost basis.
There's no way you sold the rental for $0. You sold it for a price that was clearly defined in the sales contract between you and the buyer.
Reporting the Sale of Rental Property
If you qualify for the "lived in 2 of last 5 years" capital gains exclusion, then when prompted you WILL indicate that this sale DOES INCLUDE the sale of your main home. For AD MIL personnel who don't qualify because of PCS orders, select this option anyway, because you "MIGHT" qualify for at last a partial exclusion.
Start working through Rental & Royalty Income (SCH E) "AS IF" you did not sell the property. One of the screens near the start will ahve a selection on it for "I sold or otherwise disposed of this property in 2019". Select it. After you select the "I sold or otherwise disposed of this property in 2019" you continue working it through "as if" you still own it. When you come to the summary screen you will enter all of your rental income and expenses, even it it's zero. Then you MUST work through the "Sale of Assets/Depreciation" section. You must work through each individual asset one at a time to report its disposition (in your case, all your rental assets were sold).
Understand that if more than the property itself is listed in your assets list, then you need to allocate your sales price across all of your assets. You will only allocate the structure sales price; you will NOT allocate the land sales price, since the land is not a depreciable asset. Then if you sold this rental at a gain, you must show a gain on all assets, even if that gain is $1. Likewise, if you sold at a loss then you must show a loss on all assets, even if that loss is $1
Basically, when working through an asset you select the option for "I stopped using this asset in 2019" and go from there. Note that you MUST do this for EACH AND EVERY asset listed.
When you finish working through everything listed in the assets section, if you ever at any time you owned this rental you claimed vehicle expenses, then you must also work through the vehicle section and show the disposition of the vehicle. Most likely, your vehicle disposition will be "removed for personal use", as I seriously doubt you sold your vehicle as a part of this rental sale.
