These days, low-risk bond yields aren’t enough to meet most income needs. When investing in bonds, the income typically comes as coupon payments – contractually guaranteed interest payments at predictable intervals.  There are many kinds of bond income available, so you must strike a balance between reaching for higher income (yield) and limiting risk.
Add Leverage (Mortgage) and you greatly increase the ROI especially from the perspective of using Rents (other peoples money) to pay down the mortgage and increase your equity in the property over time. At this point then yes price appreciation is secondary bonus and we have an arguement of how and why Real Estate can be better than Growth Stocks in some scenarios and for some investors.
I am a very hard worker and am willing to do whatever it takes to make a substantial income but my questions for you is how could I do this at college? How could I generate enough income from multiple sources of flow that will keep me afloat for years to come? I am in desperate need for help. Thank you very much, I would be in great appreciation if I could get a response.

To your point about Municipal Bonds, my concern is tax reform. While everything is mostly being worked behind closed doors (and likely wont ever see the light of day). There is still the chance they propose to limit the amount of the tax free nature of these bonds. While I dont sen panic in the streets, I do see a scenario where bond prices get additional pressure because municipalities have to increase rates due to people putting their money to work elsewhere.

With $200,000 a year in passive income, I would have enough income to provide for a family of up to four in San Francisco, given we bought a modest home in 2014. Now that we have a son, I'm happy to say that $200,000 indeed does seem like enough, especially if we can win the public-school lottery to avoid paying $20,000 to $50,000 a year in private-school tuition.

An obvious example is over exposure to bank stocks, which have been excellent investments for over a century.  Though a foundation of most portfolios, bank stocks do involve more risk at certain stages of the economic cycle than many realise.  Being less exposed to bank shares in the last few months could have preserved some capital.  So, a more diversified approach can help mitigate some of these risks.