There are free real estate courses online at MIT.com and Realtor.com. The courses at Realtor.com are for people wanting to sell real estate. MIT's courses are more designed for investing in real estate.
The Massachusetts Institute of Technology offers multiple free courses online. The courses include Real Estate Finance and Investment, which teaches the fundamentals of investing in real estate, particularly commercial real estate. Another course, Advanced Topics in Real Estate Finance, is a half-semester course that goes more into detail about investing in different types of real estate.
Some of the real estate courses at Realtor.com include Getting Started With Your Realtor.com Market Snapshot, Features CMA Farming Edition and Taking Advantage of Showcase Listing Enhancements.