Can I still file my taxes if I don't know where to get the info for "taxable value of homestead?"

No, if TurboTax gives you an error about missing information, you will need to enter the amount requested.

You can find the taxable value of your home on your most recent property tax statement. Also, most tax jurisdictions have websites where you can look up the assessed value of your home. Try searching for your county "tax assessor."