From the information you provided, you are still a nonresident in 2019. As you did nor receive your green card until March 2020, you were still a nonresident in tax year 2019. Your five years or part years that you are exempt from the substantial presence test are 2015. 2016. 2017. 2018 and 2019. You would start counting your days of presence January 1, 2020. You will be a resident in tax year 2020.
If you are married to a US resident or green card holder, you may be able to elect to file married filing jointly with your citizen, full year US resident or green card holder spouse. If you do this, then you can file as a resident with TurboTax. The election can be found on page 9 or Publication 519. If you make this choice you must attach a statement signed by both of you to the tax return before mailing. You will both need to declare your worldwide income.
