You can get started with TurboTax Online for 2023 here: https://turbotax.intuit.ca/tax/pricing
Or if you prefer, you can use TurboTax Download 2023, which you can find here: https://turbotax.intuit.ca/tax/software/download
You can see what we have available for previous years here: https://turbotax.intuit.ca/tax/software/prior-year-taxes
We no longer have any TurboTax products available for tax years 2016 or earlier. However, you can still download the forms for those years from the Canada Revenue Agency (CRA) here: https://www.canada.ca/en/revenue-agency/services/forms-publications/tax-packages-years.html You would need to print and mail your returns for those years.
If possible, you should do your returns in order, starting from 2013. That will make it easier if you need to carry forward amounts (ex: tuition, medical expenses, donations).