As a child I think I first learned about money by observation. When I went with my mom or grandma to the store or market, I used to be curious how a piece of paper could be used to get some meat or fish. That's probably the earliest time I learned what money actually is. And then there were also those moments when relatives give you money to buy something. Those were the earliest financial encounters I had. And then later on I wanted to buy some stuff which I had to save for first. That's financial management.
In the future this might all be digital though. And kids would be exposed to money much later than we used to.