re: After the American Revolution, how did they create a new currency?

I can't speak for the parallels between 1776 and 2024, because they're not exactly the same scenarios. However, I can tell you that after the Revolution the American people had such little faith in the national currency that many states issued their own money. As you can imagine that led to a lot of problems with exchange of goods.

Many people on the frontier had no access to paper money and lived in a bartering society, so when states like Massachusetts came looking for paper money for taxes it led to events like Shays Rebellion.

Also the same thing basically happened a few years later in western PA with the Whiskey Rebellion. There are a lot of neat stories about money in early America. The British even flooded the country with counterfeit money to drive down the faith in paper bills.