My child was born September 12, 2019. TurboTax says I should only be getting a $500 dependent credit when I believe it should be $2000. I don’t make over the adjusted gross income limit, what

Make sure you said the child lived with you all year.  That is the correct answer for a newborn.  

Go back to My Info and carefully re-read the questions and check the answers you entered for the child.  Also, make sure that you entered that the child lived with you for the Whole year since the child was born in 2019.

If the tax credit does not change after you have modified your answers, then delete the child as a dependent and re-enter.