After you file

For the Stimulus Check.  

If they didn't get your 2019 return early enough they will use your 2018 return to calculate it.  See this chart on how to calculate it.

https://www.irs.gov/pub/irs-utl/how_do_I_calculate_my_eip.pdf

 

You will receive any additional credit to which you were entitled when you file your 2020 taxes.  See question #30 here

https://www.irs.gov/coronavirus/economic-impact-payment-information-center