Did you receive the first checks of $1200 each — which were distributed last Spring? If not, you should file a 2020 tax return — even if you had no income but Social Security. On line 30 you can claim that first $1200 EACH as a refundable credit. There is free tax filing help for low income people at www.IRS.gov/freefile.
And, if you are each getting Social Security, look for a deposit of $1400 each in the same account you get your benefits. They have just started to send those out.
But if you do not get that $1400 each, please write back next month.