how do i download if possible
Yes, you can purchase and download a copy of TurboTax for 2017. To do this:
Yes. Type turbotax 2017 in your web browser and mulitple sites will show...pick one and read what is available to ensure you're getting what you need.
This link to the TurboTax web page File your 2017 taxes will allow you to select the TurboTax product you need for tax year 2017.