After you file

Of course you can file your tax return using TurboTax.  If you are legally married as of 12/31/2017 then you would file your tax return as either Married Filing Jointly or Married Filing Separately.  Use MFJ since it is more beneficial to you.

The W-4 you give to your employer for the calculating the taxes withheld from your wages is not relevant to how you must file your tax return.