The "first societies" to exist were not the first societies to use currency by a long shot. Despite some impressions from modern society, especially moder post-colonial society where specific, largely European cultural norms have been adopted worldwide, money is not a universal trait in human society. Coin currency-based money economies didn't exist anywhere until the First Millennium BCE, when it was invented at least three times independently.
I should first address cowrie shells. The most famous use of cowrie shells as a pseudo-currency today is probably from 16th Century CE West Africa. Cowries, the shells of large sea snails are relatively delicate and rare and generally considered visually appealing They're easy to carry around, so they were used as a convenient and widely accepted medium of exchange in West Africa prior to heavy European involvement. European traders, especially slavers, realized that, while rare in West Africa, cowrie shells were signficantly more common in the Indian Ocean, especially the Maldives. They began importing cowrie to exchange with West Africans because the shells were practically worthless to the Europeans despite being valued locally. The sudden influx of shells effectively tanked the West African cowrie economy.
This illustrates one of the key reasons we cannot consider cowries a true currency. As naturally harvested shells, they are impossible to standardize and control even on a local level. In that regard, trading cowries was still fundamentally a barter system, but they can be compared to currency because they have no practical value beyond being widely accepted as a store of value.
However, 16th Century West Africans were not the first people to use cowrie this way, though they may have been the people who used them most widely and consistently. There is some limited evidence of cowrie being used in a similar way in Ancient Egypt, China, and India. Like West Africa, these were all places that were either geographically removed from cowrie producing snails or with only a small cowrie snail population. In each case, the use of cowrie as a medium of exchange faded out as they became more connected with other regions and cowrie either became more common or less valued than other acceptable options.
The debate really comes down to which one should get credit for which one evolved into an actual currency, where part of the value was derrived from standardization and government support in addition to its worth as an actual resource.
So we see in all three of the earliest examples of currency that coinage evolved from pre-existing patterns of exchange (ie trading small bits of metal, often created in a reliable pattern by some authority, for their value as metal). Governments then recognized the value and prestige in standardizing and controlling these patterns and minted true coin currencies to exert greater influence in the market. That was not a new phenomenon. Many the systems of weights and measures used to gauge the value of the raw metal had all developed out of earlier states trying to exert similar controls and regulations to ensure that all trade was being conducted according to agreed upon standards as well. Those systems of weight, especially in Greece and Lydia, dated back to the Bronze Age.
The first government to issue coins in the manner described in your question (Here's some money, go use it as money) could arguably be either the Achaemenid Persian Empire, or arguably several rebel rulers within the Persian Empire. When the Persians conquered Lydia, the mint in the Lydian capital continued putting out croesids as it had before, but under Darius the Great the croesid was replaced by a pair of Persian coins called darics (gold) and sigloi (silver). They do not seem to have been intended for widespread use. From about 515-350 BCE, Persian imperial coinage was still mostly focussed on Anatolia and exchange in Greek markets. In the 4th Century BCE, local mints creating coins on behalf of local governors began popping up in the surrounding region, eventually spreading down into Phoenicia and Egypt, often to started to facilitate revolts but allowed to continue after the revolts were defeated.
Only just before Alexander the Great's conquest did a Persian mint open in Babylon, apparently responding to the same familiar pattern. With Greek and Persian coinage circulating in the west and Indian coinage in the east, coins of all sorts made their way into the Persian imperial interior and became a common method of exchange across the empire. In the areas closest to Greece, Greek coinage was so common that they were functionally a part of the Greek money economy even though the imperial government wasn't officially supporting it.