Welcome, Obed. I've been pursuing MF real estate for the past several months and here are the 3 "easiest" ways in to becoming an apartment investor. The best route depends on what you want to do in this field.
1. Investing passively in an apartment deal (syndication) as a limited partner. You find an operator you trust with a good track record, educate yourself enough to vet them and their deal, and trust them with the most common minimum investment amount: $50K. You can generally "expect" 70-110% return on your money over a 5 year period with quarterly cash distributions of 6-10%-ish. You can be an "active" passive and learn a lot about the process this way.
2. Learn to analyze (underwrite) apartment deals and submit them to Michael Blank's Deal Desk program. If you can find an apartment that meets his criteria, he'll raise the money for the deal, cut you a solid finder's fee check, and possibly keep you on the GP side to continue learning. If I could rewind time, I would go this route.
http://www.themichaelblank.com/partner/
3. Raise money for other people's deals. This has to be done carefully, but I know of one such group that raises money exclusively and through them you can join the GP side of an apartment deal and make some money too. Their business is structured in a way that complies with the legal requirements to avoid brokering securities without a license.
You can message me for more information if you'd like. Apartments all the way!
But to answer your question, if you want to get in to apartment syndications, this book is a great one stop shop for education:
https://www.amazon.com/Best-Ever-Apartment-Syndication-Book/dp/0997454326/ref=asc_df_0997454326/?tag=hyprod-20&linkCode=df0&hvadid=312025907421&hvpos=1o2&hvnetw=g&hvrand=9727541632607955792&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9026941&hvtargid=pla-598854978364&psc=1