You will probably need to have your taxes done professionally this year. You need to know what your doing to enter all this in TurboTax.
That said, for simplicity, you could just ignore it. Yes, you are better off indicating you drove the car all of 2019, and just enter your business mileage, as usual.
If you decide to go ahead:
Yes, the sales price is what the insurance co. paid you (times the business %).
No, expenses are not what you owed the bank. Loan balance is irrelevant. You most likely had no expenses of sale, so enter 0.
You say you used the standard deduction. Do, you mean you used the standard mileage allowance and did not claim any depreciation? The "standard deduction" is a personal allowance and not related to your business use of the car. Technically, the standard mileage rate includes an amount for depreciation. But the "loss" on the sale (or disposal in the case of being totaled) is usually so large that depreciation recapture is not required.
For 2020, ignore the old car, and start fresh with your new car.
