All of these numbers should be taken with a huge grain of salt, many assumptions and approximations have been made, without very detailed information about your kingdom's population and economic situation I think that's the best you can hope for.
Yearly income and debts
If one days labor nets 1 bronze, you could easily extrapolate a yearly income.
1 bronze a day x 6 days a week x 52 weeks a year = 312 bronze a year
Also equaling 15 silver 5 bronze. So for reference giving a gold coin to a peasant is more than they are likely to earn in a year.
Skilled craftsmen would obviously earn slightly more than this, as would land owners and other businessmen, but the peasants would be the majority of the population so this would be likely near the median income.
The Clergy and the Monarchy would of course take their cut in tithe and taxes. These were never fixed percentages of income, but mostly fixed fines/fees but generally overall were less than 10-20% of income. So a good approximation of their incomes would be a percentage of the income of the entire kingdoms population.
I'm going to make up some numbers here. Assuming a very-fertile kingdom populations could be around 10 people per square km so your kingdom would have a population of ~100,000 people. So assuming median income for 100,000 people and 10% for the king gives a royal treasury income of ~ 3,000,000 coppers = 150,000 silver = 7500 gold a year
So a debtor is unlikely to loan more than the entire treasuries yearly income, especially given no collateral, but an unscrupulous royal could engage multiple lenders. So debt could potentially be several tens of thousands of gold coins
A kingdom of your size would likely not even have a mint, but would instead use coins generally in circulation or only mint lower value coins. Following the fall of Rome western Europe didn't mint gold coins for nearly 1,000 years (until the Floren in ~1200), instead using locally minted silver coins (often adulterated with copper) and gold coins from the east. There would be no exact way to know the total coinage in circulation, and precious metals would often be stored by melting them down and making them into things. Barter or other exchange good contracts would be much more common, the peasant is more likely to be paid in food than coins.
The circulation would depend a lot on the economics and population of the kingdom, things like the velocity of money come in to play i.e. that peasant is likely to spend almost all of his earnings as soon as he gets them. So that peasant may only even see a few copper coins at a time and would often never have any coins.
Warning Many Assumption Again - So 100,000 people generally only needing a few coppers a piece would give you somewhere around only 300,000 coppers total in circulation. This clearly isn't enough money to pay the king, but again barter would be more common, The royal treasury could pay with food for needed labor, or would pay functionaries by allowing them to collect the taxes or fees for a region (i.e. the city guards are paid by collecting tolls at the gates etc.)