This book is an easy-to-read and short reference for all of the financial jargon / skills you'll need to know: https://financialintelligencebook.com/. Worth it to read and to be able to reference quickly. (Covers cashflow, balance sheet, working capital, etc)

Agree with others here that working with someone else at the C-level to help you come up with your own small curriculum would be great, even if they don't need to teach you themselves.