You need to do an heirship proceeding to clear the title to the property so that you can sell it. It is possible that there are judgments, in which case the judgment creditors may have liens against the property. I can give you a referral for people who can help if you're interested.
You can check the property records in Montgomery County to see whether there are any judgment liens. As far as the debts of your father, it depends on the type of debt, how old they are and some other factors.
I'm happy to talk to you about this - I'm in The Woodlands.