Shipping, Handling, Covid-19
Long story short, you're safe.
From the CDC:
“In general, because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from products or packaging that are shipped over a period of days or weeks at ambient temperatures. Coronaviruses are generally thought to be spread most often by respiratory droplets. Currently there is no evidence to support transmission of COVID-19 associated with imported goods and there have not been any cases of COVID-19 in the United States associated with imported goods.”
The contents of your package have been packed with care and caution. To keep it extra safe, you can add this shirt directly from the package to your laundry and wash in warm-hot water with a disinfectant/detergent product from this list:
And of course, wash your hands afterwards!