"Do we have to pay income taxes on our profit?"

Not to the State of Florida since Florida does not levy an individual income tax.

However, you must report the transaction on your federal income tax return (Form 1040) as well as, most likely, the income tax return for your state of residency.

I was under the assumption that once you were a senior citizen, you didn’t have to pay taxes on profit even though you report it?

Ty