Since you have filed a 2018 and 2019 federal tax return, there is nothing more that you need to do concerning the stimulus payment.
Go to this IRS website for stimulus payment information FAQ's - https://www.irs.gov/coronavirus/economic-impact-payment-information-center
Use this IRS website for stimulus payment status - https://www.irs.gov/coronavirus/get-my-payment
Use this IRS website for get my payment FAQ's - https://www.irs.gov/coronavirus/get-my-payment-frequently-asked-questions
