Firstly in the Whole World are there just 5 Main Markets?
these are what i would consider the main asset classes:
-equities (includes mutual funds and arguably traditional ETFs)
-bonds
-cash equivalents
-real estate
-commodities
-cryptocurrencies
-derivatives (includes futures and leveraged/inverse ETFs)
-alternative investment assets (includes art, collectibles, private equity, hedge funds etc)
Which one does Real Estate market fall under?
it's in its own class. it can't be considered a commodity because commodities must be fungible/interchangeable, which real estate most certainly is not. sometimes people group real estate under the "alternative investment asset" umbrella.
Any other good sites worth mentioning?
Trading view have pro and basic options but the basic free tier is enough for what you'd need starting out.
+1 for tradingview. it has all the symbols you could ask for. the free account is sorta limiting though---they won't let you save more than 1 chart, so you have to keep switching symbols to track different markets.
https://www.tradingview.com/gopro/#compare-plans