IANAL or CPA, but my understanding is that it depends on the value of the property - if it's under $15k, you're fine. If it's over $15k, then yeah, gift process applies.
1) Your dad's basis is what *he* paid for it, plus any improvements (did he run utility lines to the property? That would be an improvement, and can be added to the basis).
2) When he gifted you the property, it means you got HIS basis.
3) HE was supposed to file a form with his taxes in 2019, noting that the gift exceeded the $15k gift exclusion threshold for the year. If he didn't file that form, I would work with him to submit a revised 1040 for 2019, including this form.
4) The giftee never owes taxes for the gift, so YOU are fine.
5) Now, if you are selling, you subtract the sale price from the gift's basis, and end up with taxable profit, or a loss. If there is no profit, no taxes are due. And since it's a "personal" loss rather than investment loss, I don't think you can claim a loss on your taxes.
This is my understanding of the process, but do not rely on it for legal advice. Consult your own lawyer or CPA to confirm.