Before delving into accounting, I would ask someone if they knew the difference between a stock and a bond. Some recent college graduates I have talked to did not know. They should also know what mutual funds are.
Have that information down in spades.
Good. There are tons of books on investing for adults who are not in the profession. Maybe some in the "Little Book" series would be appropriate, for example
The Little Book of Valuation: How to Value a Company, Pick a Stock and Profit
by Aswath Damodaran
The Little Book That Still Beats the Market
by Joel Greenblatt and Andrew Tobias
The Little Book of Value Investing
by Christopher H. Browne and Roger Lowenstein