Well, not everyone: everyone who files a tax return. $1000 for each single person, $2000 for a married couple filing jointly. The payments would be offset by any cash payment you’re already getting: for example, Social Security, disability, or unemployment. People in jail or prison would be ineligible.
In round numbers, you’re talking about $1.5 trillion, or less than half the Federal budget, or 10% of GDP.
The program would be financed not by taxes, but by special bond issues which would be purchased, directly or indirectly, by the Federal Reserve. The Fed would hold the bonds indefinitely, and return the interest to the Treasury.
The program would be reduced or eliminated if inflation rose: say, 10% for every 0.2 above 5%. So, for example, payments would be reduced by 50% if inflation hit 6%, and eliminated at 7%.