what will we do when the government goes out of buisness?

By defaulting on their bonds, either honestly by admitting they can't pay it, or dishonestly by printing enough dollar bills to pay for it- which will lead to hyperinflation.

I suspect we will just destroy the value of the dollar, which is the wrong way to default.

They don't file for for bankruptcy. They simply keep issuing Treasury securities, sell them to the highest bidder. The Treasuries the Fed buys, are bought with money printed from nothing, with no value. They will continue to borrow, and print the debt, devalue the dollar, until the dollar collapses. They will most likely at that point issue a new currency, and pay .10 cents on the dollar for the exchange.

I'll just stay on my farm and hope my animals all have big litters etc to keep me going. Especially them draft horses. Need em to plow in the spring.