As a start, separate "derivatives" (a huge category of products) into two simpler categories: listed options and futures. For many underlyings, like interest rates or commodities, it is very difficult to trade the underlying directly, so you use derivs to trade them indirectly.

Related: My biggest concern: There should be more gatekeeping around allowing retail traders access to derivs markets due to the implied leverage in the contracts. That said I don't know a good way to gatekeep. How about an exam?